Are skyscraper ads (extra-extra long vertical banners) right for you? Suhaila Suhimi-Waldner, Senior Traffic Builder Hook Media, started buying skyscrapers more than a year ago for a B-to-B client who was trying to reach C-level executives in the Fortune 500. She says, "Given that this audience can be found in mostly- content-rich sites such as Forbes.com and ZDNet.com, I felt a regular banner ad would not be as effective as it would disappear when the site visitor scrolls down a page to read the content."

Did it work? Suhimi-Waldner says, "Results were phenomenal! In addition to getting an increased number of leads, my client reported that the leads were much more qualified, due to the flexibility of bring able to convey more in the banner." Suhimi-Waldner's tips for other B-to-B online media buyers:

- Skyscrapers may be the killer app, but you should still run small test campaigns on each and every site before you make any major commitments.

- Although skyscrapers tend to yield higher click throughs due to visual impact and novelty, they also cost more to run. So it's important for you to measure campaigns according to your final goals (sales leads, actual sales, qualified visitors, etc.) Make sure your conversion rates from click throughs are high enough to justify the extra money you're spending.

- Having a strong call-to-action on a banner is crucial. Strong incentives and multiple links tend to work well. Test banners to learn what works for you; never just run with a single creative.

- According to the IAB, the standard ad dimensions of a skyscraper are either 160x600 (wide version) or 120x600. However, actual sizes available on sites Fortune 500 execs frequently visit still vary:

RedHerring.com - 143x700
BusinessWeek.com - 140x800
Forbes.com - 150x800
WSJ.com - 120x400
ZDNet.com - 148x800