There is much to search engine optimisation that I have not covered, but getting to the bottom can only happen when you get the fluff filtered away so you can focus on the real stuff.

If you rely on tricks and tweaks to yield large results on Google, you may find yourself spending many resources with little effect.
There may be some that work, but you can be certain that if it brings an unfair advantage - i.e. searches yield results with little to no relevance - Google will find it and close down the trick, leaving you to spend more resources on finding the next trick, and so it goes on.

By relying on the content, you will not only make your site easy to crawl - you will also cater for the visitors... and that is still the important part, isn't it?