It always seems to be SEO vs. PPC. Both of them vying for attention and trying to take all of your advertising dollars. When it comes to SEO, sometimes it’s hard to know which keywords are the best ones to optimize for. This is where you can bring in PPC and specifically Adwords. So many SEO’s scoff at PPC, but they often forget some of the simple benefits any SEO campaign can gain from a small $50 spend in PPC.
http://www.seo-scoop.com/2010/02/26/using-ppc-to-boost-seo-campaigns/