Using real world numbers, tested with actual landing pages, it has been shown that you can increase the amount of money made from search engine optimization, even if you already show up #1 for the term you want to show for. How’s it done?
Turns out that its not a waste of money, or click cannibalism if you purchase pay per click keywords for search terms that you already show up for organically using search optimization. Check out this article where they tested how pay per click effects your bottom line, using conversion rates, and analysis of traffic that comes from a double listing using search engine optimization and pay per click advertising on the same keywords.
To sum it up, or to put my interpretation on it though…
1. You can build custom landing pages for PPC. So the conversion rate can be better.
2. You get some credibility trust worthiness before the user even comes to your site, with a double listing.
3. Its always better to test a theory than to just assume its right.