Since 1994, when banner ads first appeared on the internet, there has been a considerable increase in its use in online marketing. More and more individuals and companies are turning to banner ads for advertising their services, products and websites.

Banner ads yield two benefits. First, they may entice users to click on the banner and go to the advertiser's site. Each time this happens is called a "clickthrough", and the number of clickthroughs divided by the number of impressions is called the "clickthrough ratio" or "click rate". This is easy to measure, and provides a direct measurement of a banner's effectiveness.

The second benefit of ad banners is building brand recognition. Despite ad agency claims to the contrary, this is almost impossible to measure. User surveys and market research can provide clues, but they are very imprecise and conjectural compared to the straightforward business of measuring clickthroughs and site traffic. Whether brand recognition is part of your strategy depends entirely upon your individual situation. If it is, then things like click ratios and conversion rates can't be used as absolute criteria, and the process of measuring effectiveness becomes much more subjective.

But if you want those ads seen, you'd better make them compelling.

New surfing tools have been created precisely to block your ads. InterMute (www.intermute.com) and AtGuard (www.atguard.com), for instance, block banner ads, animated GIFs, pop-up screens and even background sound - greatly cutting down site loading times.

How do you fight back? Make your ads so intriguing, surfers won't want to block them. Sure, it's a daunting task, but you've got 7.7 billion reasons to try.