Kevin Lee explains the concept of "search scent," —If your paid placement landing pages don't reinforce the search scent, you lose too many visitors to the "Back" button. Moreover, because Google has incorporated landing page relevance into the Quality Score, you overpay for clicks (or miss out on higher positions at the same CPC (define)). Yahoo's phase two of Panama is imminent, and if you haven't revisited your ad creative in preparation for Yahoo's new ranking algorithm you'd best get cracking.
With phase two of Panama, search scent is important in ad creative, too. Generally, applying search scent to the ads in your PPC (define) campaign will improve performance, but there are times too much scent can be a bad thing. If you're going to outsmart the competition and maximize profit, you must know when and where to use scent and how to make it seem natural.