My friend and partner, Andre Savoie has written a great blog post on the subject. If you didn't already know it, it is great for your business to show up on page one of a search organically. And it is great to be visible with paid advertising, like Google AdWords.
But if your company shows up for both, well read on:
"We have always been of the mindset that 2 page one listings in Google are better than one, so being good at SEO doesn’t mean you should avoid paid search marketing. After all, for every spot you claim you are knocking a competitor off or out of the way. By claiming this territory, especially above the fold on page 1, people who search are getting the message that your business must be trustworthy to show up in both places." Full post.