it's a topic that has been thrashed about and discussed on these boards ever since the promotions started. There appears to be no detectable rhyme or reason as to who gets 'em or why, it's just an indiscriminate random distribution. Undoubtedly eBay have some kind of criteria themselves, cooked up by their marketing team, but I'd bet all the money in my pocket that they'll never share their marketing strategies.

So for we mere mortals, it's all just assunmption and guesswork and a case of cross ya fingers and hope some come your way eventually.