Use a call to action
Drop users as close to the bottom of funnel as possible
Show prices
Sweeten the deal with promotional language

Most of these will in fact help increase click-through rate (CTR), the metric on which most marketers rely as a proxy for an ad compulsion. Whether we should equate CTR with compelling depends on what we would like to compel the user to do, and how we track that behavior.

A recent Yahoo! Search Marketing/Comscore study tracked purchases generated for an online consumer electronics retailer. Eight percent of those conversions occurred online. The rest: offline. What happens if those marketers only track - and optimize for - online behavior? Perhaps they will find that free shipping, low-price guarantee, and a wide selection drive the highest CTR and online sales. What are the other 92 percent compelled to do? Certainly not visit over 300 locations or take advantage of in-store pick-up. In this example, by tracking and optimizing only online behavior, the creative would optimize away from where the majority of dollars are spent.

How do we account for consumers who interact with our online brands to gain awareness and build consideration, but do not buy right away?

How do we account for the fact that most online consumers view multiple pieces of display media, conduct multiple keyword searches on more than one search engine, and click on both organic and natural listings?

If we don't pay attention to how consumers choose to interact with online brands, engage in the online experience, or shop for products, then we will find it hard to compel them to do anything.

Our initial research suggests that the attribution of an online sale to the last click (and optimization of that respective keyword or banner) is likely discordant with actual user behavior.

Speaking of discordant, am I the only one who has noticed the presence of an umlaut among Search Engine Strategies exhibitors? For those of you who did not take German in high school or listen to Motley Crue, an umlaut is a marking placed over a vowel to indicate a different articulation of the word. Like Google's spectacular IPO, does the presence of an umlaut in an SEM name indicate that search has reached new heights? Perhaps umlauts are most compelling to marketers who either listened to the Crue in high school or in college.

I would be remiss in a discussion on compelling advertising if I did not mention the presence of booth babes at the Search Engine Strategies conference. According to Wikipedia, "booth babe is a semi-slang term referring to attractive persons hired specifically to draw attendees into the booths of commercial exhibitions. These persons are not regular employees of the company, but are typically freelance models." What were these female models doing wearing mini tank-tops with the (rhetorical) question 'wanna be on top?' in one exhibitor booth?

Well, if they did not want to sell their SEO services to women, they were doing a good job filtering. If they wanted to avoid pitching their services to guys who were in the exhibit hall at a search conference to learn about search rather than chat up models, they were doing a good job shunning that crowd.

When I walked by the booth in question (quickly, with my hand shielding my eyes), I did glimpse lots of foot traffic. I wonder if those compelled to answer the question were also compelled to buy SEO? A loud rendition of Motley Crue "Girls, Girls, Girls" might make the booth even more compelling. But will it help sell more SEO?

This commentary is insightful. I recommend it to others.