Which letters/digits they use in Pepsi cap codes

Doctor Q

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Last year, I had a lot of trouble with the legibility of the codes inside the winning Pepsi/iTunes caps. I would sometimes have to guess what a letter was, e.g., M vs. N or U vs. V. I'd type it one way, have it rejected by iTunes, and type it the other way(s) until I got it right. I'm sure I wasn't the only one who ran into this problem.

This year, the codes are much more readable. They are printed in a clearer style and appear darker. Since I've won a good number of them so far, I had a good sample size with which to study the codes they use, which are alphanumeric (made from letters and digits) and each 10 characters long, e.g., P3E4P 6S7I9.

I found that they use these 29 digits and letters:
3 4 6 7 9
A B C E F G H I J K L M N O P Q R S T V W X Y Z​
and they never use these 7 digits and letters:
0 1 2 5 8
D U​
The reason is clear: legibility! This way, we can't confuse 0-D-O, 1-I, 2-Z, 5-S, 8-B, or U-V.

To test this theory, I decided to use look-alike characters when entering codes for tunes I won. I started with some caps that had Os. I found that I could enter either O or 0 for an O on a winning cap and it would be accepted by iTunes. The same for Is: you can type either I or 1. And the same for Us; you can type either U or V.

This was nice work by Pepsi/Apple, and I appreciate it. We get fewer frustrations; they get fewer annoyed customers or service calls.

I'll have to win some more caps before I can try entering D for O, 2 for Z, 5 for S, and 8 for B. If you have any winning caps with O, Z, S, or B, please enter it as D or 2 or 5 or 8 instead and post here to tell us if it worked. There is only about a week left in the promotion!
 

Dr. Dastardly

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WOW pretty impressive foresight their part. Wouldn't of thought about it myself but now that you point it out it seems so obvious. I wonder if this was a problem last time and thats why they thought to do this.
 

Doctor Q

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Dr. Dastardly said:
I wonder if this was a problem last time and thats why they thought to do this.
I assume it was. Hey, maybe they did it just for ME!

Now, just to be compulsive (who, me?), I considered that my results could in theory be random luck.

In theory, it could be that they use all letter and digits in their codes and it was just random chance that my particular collection of caps had no 0s, 1s, 2s, 5s, 8s, Ds, or Us.

However, I've won 64 tunes so far (my method is patent pending) and I've computed the odds of my caps having only those letters and digits if Pepsi used them all:
Odds: (29/36)^(64*10)

Reason: There are 29 letter and digits in my caps.
There are 36 possible letters and digits.
I have 64 winning caps.
There are 10 letters and digits per cap.​
That means there is only one chance in 80×10^60 (eighty times ten to the sixtieth power) that my results were simply luck. That's one in 80 decillion in the British usage and one in 80 novemdecillion in the American usage, a number so big that you probably never heard of it!

And, of course, the particular letter and digits that don't occur in my caps are ones that can be confused typographically.

Suffice it to say that I'm convinced that they purposely limited their choice of letters and digits.
 

homerjward

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Dr. Dastardly said:
WOW pretty impressive foresight their part. Wouldn't of thought about it myself but now that you point it out it seems so obvious. I wonder if this was a problem last time and thats why they thought to do this.
forget the foresight, it's pretty impressive he figured it out! :eek:
 

Nermal

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Doctor Q said:
To test this theory, I decided to use look-alike characters when entering codes for tunes I won. I started with some caps that had Os. I found that I could enter either O or 0 for an O on a winning cap and it would be accepted by iTunes
Once you've bought a song with O, can you then go through again and use 0 and get another song? :D

And if so, can I have a free song or two for coming up with the idea? ;)
 

pdpfilms

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Once you've bought a song with O, can you then go through again and use 0 and get another song?

And if so, can I have a free song or two for coming up with the idea
Unfotunately, according to what he's saying, that won't work..... that's why they don't use those letters in the codes. for instance, the code 03E40 6S7I9 and o3E4o 6S7I9 would be one in the same... enter in one, and the other becomes void. Sorry.

However, I've won 64 tunes so far (my method is patent pending)
Patent Pending, eh?? Hmmm.... you wouldn't be tipping the bottle, would you?
 

dotdotdot

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Jan 23, 2005
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You went and counted 64 bottle caps numbers??

Uh... yeah... uh... theres... uh... nothing wrong with that... :rolleyes: :p
 

Doctor Q

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dotdotdot said:
You went and counted 64 bottle caps numbers??
Not exactly. I looked them over to see if I could find the whole alphabet and all ten digits. And, all by myself, without even a calculator, I figured out that there were 640 letters and digits in all by multiplying 64 by 10. Clever, eh? ;)

pdpfilms said:
Patent Pending, eh?? Hmmm.... you wouldn't be tipping the bottle, would you?
OK, since you twisted my arm, I'll tell you my patent pending technique:

1. Find some coworkers who don't care about iTunes (I'm surprised there ARE such people, but it's true in my case).

2. Get them to agree to switch from canned Pepsi to 20oz bottles for a month or two. (We buy them together in bulk.)

3. Get them to agree to give you their winning caps in exchange for hearty thanks.

4. Drink Pepsi instead of your usual favorite (Dr Pepper).

Here's a photo of my winners so far. I took this shot while setting up the shot I'm using for my avatar this week. Which is why I had all the caps laid out. Which is why I thought to look at which letters were used.
 

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Harry K.

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As cheap as it sounds, no one in my family drinks coke or pepsi or even a lot of soda for that matter, so my father (who recycles on a regular basis) asked the lady in charge of the recycling center to save winning caps for us.

She deserves a great thanks- we've gotten about 20 winning caps so far + a cap that gives a free 3 liter coke!
 

Doctor Q

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My wife just opened a Pepsi and won again (that's number 65), and by luck she got a code with both a B and a Z.

When entering it, we typed 8 instead of B and 2 instead of Z and it was accepted!

So all that remains to prove the theory about the lookalike characters is for somebody to get a code with an O or an S. If you get an O, type a D instead. If you get an S, type a 5 instead. Then post here to report if it was accepted. There's no risk; if it isn't accepted, you just correct it and click again and it'll then be accepted.

Edit (the next day): We got winner number 66 today, and the code had an "S". We typed "5" and the code still worked! The last test is to find a cap with a letter O and type letter D instead.
 

Doctor Q

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tech4all said:
How long did it take to get to 65? That sure is a lot of Pepsi! :)
Urp! Yes it is.

It took a little under 2 months, which is how long it's been since the third week of the promotion. We didn't have the Pepsi/iTunes bottles in stores here at first after the promotion began January 31st. But I've had half a dozen thirsty people helping me on and off since then.
 

Doctor Q

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Tee hee. I couldn't resist taking a snapshot of the display when I used my 65th cap to buy a certain Keane song.

I guess you're not allowed to interrupt the downloading of this song! :D
 

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vieoray

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i know someone who works for pepsi. he drives a truck, and he gets a discount on pepsi products. before the promotion i asked if he used iTunes, and he said he didn't, so i got him to save all his caps for me. he also saved the caps of his friends from work. its worked out nice :)

very interesting, doctor q.
 

Doctor Q

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vieoray said:
i know someone who works for pepsi. he drives a truck, and he gets a discount on pepsi products. before the promotion i asked if he used iTunes, and he said he didn't, so i got him to save all his caps for me. he also saved the caps of his friends from work. its worked out nice :)
How many?
 

PlaceofDis

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i was about to say.... i have gotten both Z and 2 in my winning caps, as well as a B i believe
 

Doctor Q

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PlaceofDis said:
i was about to say.... i have gotten both Z and 2 in my winning caps, as well as a B i believe
According to my theory, you could have gotten a Z and a B, but not a 2. Is the cap still around so you can check?
 

PlaceofDis

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Doctor Q said:
According to my theory, you could have gotten a Z and a B, but not a 2. Is the cap still around so you can check?
i dont have the cap but i know it was a two because i remember entering it as a Z at first, because thats what i though it was, i had to figure out the problem and turned out that Z really was a two! annoying to say the least
 

Doctor Q

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PlaceofDis said:
i dont have the cap but i know it was a two because i remember entering it as a Z at first, because thats what i though it was, i had to figure out the problem and turned out that Z really was a two! annoying to say the least
How surprising. That shows that my theory about the missing letter is wrong, at least for the 2. I will watch for further Zs or 2s in my own caps and try entering them as the other.
 

PlaceofDis

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Doctor Q said:
How surprising. That shows that my theory about the missing letter is wrong, at least for the 2. I will watch for further Zs or 2s in my own caps and try entering them as the other.
i personally doubt they have too much control over which letters/numbers are possible, after all they have to come up with a certain number of codes, and while there are a lot of possible combinations, there probably is a program that comes up with the codes, they probably just try not to use certain numbers/letters, but some are bound to get through
 

clayj

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PlaceofDis said:
i personally doubt they have too much control over which letters/numbers are possible, after all they have to come up with a certain number of codes, and while there are a lot of possible combinations, there probably is a program that comes up with the codes, they probably just try not to use certain numbers/letters, but some are bound to get through
You are correct, sir. There's an algorithm that's used to process the code that you enter, to make sure it's valid... this is designed to prevent people from just sitting there and typing in "random" codes. The odds of any given possible code actually being valid are VERY low.

A similar system (patented, actually) is used by Microsoft... the product key for Office or Windows (or other Microsoft apps and products) is a 25 character code that uses any letter or number, but no vowels, zeroes, or ones (29 characters), to produce over 10^36 possible codes. Within that code is encoded the product, its platform, its version, and a host of other information. It's basically impossible to forge a Microsoft product code if you don't already have one... the algorithm, of course, is highly complicated and EXTREMELY secret. (And it's not stored on your machine... it's stored on a Microsoft server and is used to validate your product activations.)
 

PlaceofDis

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clayjohanson said:
You are correct, sir. There's an algorithm that's used to process the code that you enter, to make sure it's valid... this is designed to prevent people from just sitting there and typing in "random" codes. The odds of any given possible code actually being valid are VERY low.

A similar system (patented, actually) is used by Microsoft... the product key for Office or Windows (or other Microsoft apps and products) is a 25 character code that uses any letter or number, but no vowels, zeroes, or ones (28 characters), to produce over 10^36 possible codes. Within that code is encoded the product, its platform, its version, and a host of other information. It's basically impossible to forge a Microsoft product code if you don't already have one... the algorithm, of course, is highly complicated and EXTREMELY secret. (And it's not stored on your machine... it's stored on a Microsoft server and is used to validate your product activations.)
thats interesting, just imagine if someone was able to crack that though, that would be a huge mess LoL, and i imagine the person who came up with the original coding and algorithm had to be paid big bucks not to leak it, i find all of this fascinating of course because im a geek
 

clayj

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PlaceofDis said:
thats interesting, just imagine if someone was able to crack that though, that would be a huge mess LoL, and i imagine the person who came up with the original coding and algorithm had to be paid big bucks not to leak it, i find all of this fascinating of course because im a geek
Well, don't forget that the processing of product codes is handled on the SERVER... so even if you figured out the algorithm for whether a product code is *valid*, you'd still have to know what elements went into it to determine the product, version, platform, country, and all sorts of other stuff. In other words, if I knew the algorithm to determine if a code is valid, I still don't know what needs to be IN the code in order for the server to validate. I might accidentally come up with a product code for the Japanese version of Office 2000, rather than for the American version of Windows XP SP-2.

FWIW, I did see a web page once inside Microsoft that talked about the stuff that's encoded in a PID (Product ID)... it's HIDEOUSLY complicated. No one's ever gonna break it... and even if they do, if they notice a particular product code being used repeatedly, they can just terminate that code from the server and render it useless.
 

PlaceofDis

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clayjohanson said:
Well, don't forget that the processing of product codes is handled on the SERVER... so even if you figured out the algorithm for whether a product code is *valid*, you'd still have to know what elements went into it to determine the product, version, platform, country, and all sorts of other stuff. In other words, if I knew the algorithm to determine if a code is valid, I still don't know what needs to be IN the code in order for the server to validate. I might accidentally come up with a product code for the Japanese version of Office 2000, rather than for the American version of Windows XP SP-2.

FWIW, I did see a web page once inside Microsoft that talked about the stuff that's encoded in a PID (Product ID)... it's HIDEOUSLY complicated. No one's ever gonna break it... and even if they do, if they notice a particular product code being used repeatedly, they can just terminate that code from the server and render it useless.

ah yeah, but still hacking the algorithm would be quite a feat in and of itself, i suppose there would be more damage done if the Servers were hacked then, which i wonder how often that happens are attempts are made to hack 'em