That's not really a true-true-related statement. Adverts are supposed to have an affect on sales, otherwise people wouldn't spend money on them.
That's like saying Budweiser's superbowl commercials boosting sales of Budweiser must mean that Bud beer is better and people just didn't know about it. Or something like that.
arn
Effect Arn!
I think that individual apps could perhaps warrant their own advertisements, considering how wildly popular the app store seems to be. The combination of the quality and low price of the apps compared to what people are used to is phenomenal. Crappy java games cost more on my old phone, and they really were woeful in comparison to iPhone software.