Even from some of the great agencies I've seen slop on the web. No doubt some CD in their 60s started explaining to their young creatives about how to write for young people. They probably said something like "look on the web, you just need to be random and stupid, that's what is viral, just something crazy!!!" And you know what...they're wrong. There is a deep sophistication to stuff that's popular on the web (tits and weird foreigners singing aside).
To an untrained (elder) mind, it may seem random, but it's the circular randomness (stupidity returning back on itself) that the web is great at. There seems to usually be some constant thought throughout whatever silly thing it is. Plus, (and this is crucial)it's not stupid done stupid, it's stupid done smart.
Also, webstuff is created in the author's voice. There are popular clips and websites from older web-folk, but they're not pretending that they're young and hip. I
That, and once something has been done, it's dead. If it's already popular on the web, you will find harsh blog backlash if you try and do it again.
I'd say the most obvious proof of how little most agencies get the web are their own websites (excluding Wexley School for Girls
perhaps). If there are other amazing agency websites, drop a line and I'll update the post. I'd love to be proved wrong on this one.