Which kind of ad would you have been most likely to click? Was this because the ad was superior or simply because it matched your idiosyncratic preferences better? (If there is only one ad, analyze how well it appealed to you.)
Analyze the ads. Do the ads all appeal to different segments or do they all seem to be appealing to the same segment of customers? (If there is only one ad, analyze what kind of customer the ad appeals to and what other kinds of customers might be doing the same search that the ad misses.)
Click on the ad that appeals to you most. Analyze the quality of the landing page. Does it match the message in the ad (consider product, price, promotion, keywords)? Does it encourage conversion?