IN the past six months, I've audited over 100 AdWords accounts. I was not surprised to discover the better performing accounts were the ones with better Quality Scores … I WAS surprised when I realized there was a definite difference in PPC results for clients actively engaged in (best practice) Search Engine Optimization!
I used to advise people very strongly to hold off on their search engine optimization efforts until after their initial pay per click (PPC) work was done. That's because I thought it was essential to identify your "Money Keywords" first … so all your SEO dollars could focus on these.
However, the way things have been evolving, Google now seems to seriously consider your level of "authoritativeness" across the entire vocabulary of your market when they evaluate your PPC Quality Score.
Given the increasingly shark infested, brutally competitive environment which AdWords has evolved to become, it's now almost essential to have an authoritative site for your market in order to accomplish anything in PPC.
Pay per click prices for the "stand alone" site, not well integrated into the community of the market it intends to serve are becoming just too high for most vendors to make a go of it.
Moreover, the ongoing bidding wars in PPC make it almost essential to "dollar cost average" by including organic, free traffic in their overall strategy.
I'm therefore now recommending a mixed approach to Internet marketing. If you are focusing all your efforts on pay per click search marketing, now is the time to start paying attention to SEO as well.