Which Came First: the Chicken or the Advertiser?

We're all familiar with the age-old industry debate: Does advertising influence society or does it merely reflect it?

If recent marketing efforts are any indicator, it would suggest the latter, as marketers try desperately (and somewhat unsuccessfully ) to latch on to consumer-generated trends. Goliath retailer Wal-mart has attempted to re-create it's own MySpace . Both Yahoo! and Mentos are launching their own consumer-generated media contests this week. In addition, marketers are showing a growing interest in 'casual games' .

Will these efforts be fruitful? Now that the consumer generated "create your own ad/video" phenomenon seems to have run it's course, it seems doubtful. Perhaps the question is not a matter of which came first but rather which serves a better purpose? Isn't advertising far more effective when it influences rather than imitates behavior?

Your thoughts/examples...?