if I choose to buy credits, because I have a friend in Canada I'd like to text frequently, but I've (we've) never done, because of the outrageous costs... if I bought credits, do they automatically take effect? I mean, if I start texting her # through biteSMS, it AUTOMATICALLY bypasses the AT&T detectors and won't double-charge me on my bill or anything? if so, how exactly does that work? but I"m under the impression that is how it would work, is this correct? I buy credits, text her, the texts start coming off of my purchased credits and I never receive charges from AT&T? How's that possible without them knowing I am texting her? I'm confused.