While in the old days, this would no doubt have come from Creep McShady in a trench coat around the corner of some noir-esque alley, now its online fraudsters who've gamed Apple's iTunes gift certificate generation algorithms, unable to sell directly due to fear of Apple tracing the accounts, who've found a new target for their schemes. Says Apple Insider:

Third party iPhone App Store developers have received propositions from a scammer offering to buy large volumes of their iPhone applications and then split the resulting revenue with them, apparently using fraudulent iTunes gift certificates to make the purchases.

Of course, the developers faces every bit as much chance for retaliation from Apple, perhaps more so because this could end their careers as iPhone developers.

Yeah. Not a good idea.