By Tony Nethercutt

The audience available on the mobile Web is growing rapidly. Consequently, the interest in mobile advertising is growing rapidly. When an agency or advertiser asks about buying advertising on the mobile Web, they typically ask questions about media buying and questions about creative.

This month I begin a two-part series covering the media buying fundamentals of mobile advertising. After I cover media buying, I will shift my focus to the creative fundamentals of mobile advertising, telling you more about landing pages and strategies for the ads themselves.

In addition to creative, I will discuss the targeting options available on the mobile Web to help you reach your target audience.

The three questions most often asked about how to buy mobile media are: What can I buy? How is it priced? How much do I need to achieve my desired impact?

This month I will cover the first two questions. Stay tuned for next month, when I will address the "How much do I need" question.

What to buy
Advertising on the mobile Web is very similar to Web advertising. Many people try and make it complex, but it really isn't. The primary ad units are very similar to the ad units you are used to buying on the Web: Graphical banner ads and text link ads.

I recommend a mix of banners and text depending on your goals.

For a brand advertiser, I typically recommend a mix of 50 percent graphical banner ads and 50 percent text link ads to allow advertisers to achieve both brand building and performance goals.

If your goals are 100 percent brand-building, then go with 100 percent banners. If your goals are 100 percent ROI, then go with 100 percent text link ads.

Both banners and text ads appear on mobile Web sites for visitors to see when they are browsing the mobile Web from their phones (not text ads in an SMS message).

Size issues
The biggest difference you will notice between mobile banner ads and PC Internet banner ads is that mobile ads take up a large percentage of the screen, often 25 percent or more.

The size of the ads and the fact that someone viewing the page has to scroll right through the ad to view the content below has led to click-through rates that are consistently five to 10 times higher than the average for banners on the PC Internet.

The fact that there is most often only one mobile banner ad on the page also helps create real value for the advertiser.

Graphical banner ads are images like their Web counterparts. In mobile, however, graphical banner ads are always served across the top of the page and take up the full width of the screen.

Unlike PC Internet banner ads where bigger banners are more expensive, mobile banners are all priced the same, regardless of size, because phones have different screen sizes and the best fitting ad for the phone is dynamically served.

There are four different ad sizes that we and the Mobile Marketing Association recommend so that we can optimize on the fly, and always serve the best fitting ad for each phone -- resulting in a better user experience and even better performance.

Most familiar PC Web advertising tactics are also common in mobile.

Various forms of targeting, sponsorships, roadblocks, keywords and even rich media are available today. I'm focusing on discussing display advertising ad units, but if you're a keyword advertiser on the PC Web, you'll likely be a keyword advertiser on the mobile Web as well.

Brand advertisers are using studies by Dynamic Logic, Insight Express and others to measure brand metrics, and direct response advertisers are measuring their effective CPA -- just like they would expect to be able to do.

Many agencies are placing buys through MediaVisor and Atlas, just as they would expect to be able to do. My point is that mobile media buying is as familiar as it is easy.

How is it priced?
Mobile Web text link ads are sold on a CPC (cost-per-click) basis and graphical banner ads are typically sold on a CPM (cost-per-thousand-impressions) basis.

Some ad networks also sell banners on CPC. Typical CPMs in mobile advertising range from $10-$50, depending on the targeting, the site and the organization you are buying from -- site direct, site-specific ad network, blind ad network, et cetera.

Now that we've covered the basics of mobile media buying, including the available ad units and pricing, you're ready to think about the size of your buy. Stay tuned for next time when we get into the details of sizing your buy.

Tony Nethercutt is vice president of sales at mobile ad network AdMob, San Mateo, CA. Reach him at