I think Search Engines are overrated. I have my work who is a top 10 recruitment site and I run a personal top 10 film site. The traffic from Search Engines are good but nothing compared to other methods of promotion.
The recruitment site gets 1000% more traffic from other marketing methods and my film site had a huge spike when it was linked from
www.fark.com and I talking 8k visitors rose to 35k from one link on Fark. Fark seems to have got there visitors from a sense of community and boobs rather than search engines.