Google AdSense is reinvigorating the online advertising landscape. After a few years of drought, people can earn money from advertising again ­ this time, real money and not just pittance barely enough to cover hosting fees.

The dot-com crash brought along with it the fall of online advertising, particularly for small publishers. Rates plummeted to all-time lows. Whereas small publishers could earn as much as $50-100/cost per thousand (CPM) in the mid-to-late 1990s, ad earnings precipitously dropped to $0.20-0.60 cents per thousand impressions in 2002. Site owners had to scramble to find other means to earn a living from their Web sites!

AdSense is a text-based ad delivered by Google, today’s leading search engine. The ads come usually in the form of the leaderboard (728 x 90), standard banner (468 x 60), skyscraper (120 x 600) and inline triangle (300 x 250). The colors of the ad box and fonts can be customized to fit or contrast with the site's color scheme, whichever the user chooses..

What sets this program apart from other text-based ads is that it delivers ads that are contextually relevant to your audience. It uses an advanced and proprietary technology that determines the content of each of your site’s web pages, and then delivers the ad based on that content. Just as readers of special interest magazines welcome ads on topics of interests to them, the visitors of special-interest web sites are happy to see ads relevant to their craft, business, hobby or interests. A Web page on home business would likely receive targeted ads on “starting a business,” while a music site may receive targeted ads on music CDs. The ads automatically adjust for each page’s content.

The underlying thinking is an ad targeted to the audience of a Web page will generate higher response. Ads placed in context ultimately become a content point, seemingly blending with the content of the page that the user is visiting. This in turn increases the ad’s relevancy. The more relevant an ad is to the page, the higher its effectiveness and click-through rate, and the greater the income potential. That means more click-throughs for the advertisers, and more dollars for the publisher!

One Internet guru described AdSense as a “money machine where you simply sit back and watch the money roll in.” And for the right Web site, AdSense is proving to be a most welcome cash generator.

Free and easy to join and implement, AdSense offers Web site owners a source of ongoing advertisers that will never run dry (well, at least for now). You now have access to a new set of advertising spenders and marketing companies who have advertising budgets to work with.

Instead of spending your time hunting down your own advertisers, you can focus more in creating solid content for your site. You can work the content of your sites without worrying very much about the costs of self-publishing information on the Web.

The reduced workload and potentially good income are enough incentives for small publishers to apply in droves to the program.

Alas, AdSense is not for everybody. Just as the initial euphoria has leveled off, complaints of AdSense’s inability to serve them the right ads ­ or any ads at all ­ can be heard on various discussion boards and forums. Some sites complain of not getting any relevant ads. Worse, some are getting ads from charity organizations, which are non-paying ads.

Who is Google AdSense especially suited for? It's EXCELLENT for those who already have, or for those who want to start, high quality, theme-based content sites, with excellent keyword-focused content pages. Better yet, your site must have keywords where advertisers pay a premium to reach. That can range from a wonderful little hobby or passion site to a full-blown information site by a major company.

Your income will also be commensurate to the level of traffic that your site generates: the more traffic you have, the greater the potential income. A site that attracts 1 million impressions has the potential to earn more (even at a 2.5% clickthrough rate) compared to a site that attracts 1,000 impressions per month ­ unless the smaller site has higher paying keywords and better clickthrough rates. Higher clickthrough rates, however, are subject to tighter scrutiny by Google. A site suspected of fraudulent clicks can be kicked out from the program.

Lessons from other forms of advertising (banners, interstitials, popups and popunders) show that users have learned to ignore advertising on the Web.

However, text ads like AdSense are benefiting from a novelty effect. It is still so new that users haven’t yet learned to ignore them. According to Jakob Nielsen, users in the long-term can “develop box blindness, ignoring little text boxes just as they've long ignored banner-shaped areas of the screen.”

Nonetheless, Google AdSense has brought back to small publishers the opportunity to leverage their content through advertising. It is bringing an excellent earning stream to some Web owners, with monthly revenues reaching the thousands, even more. Not since dot-com "boom" times had the Internet world seen CPM and click through rates this high.

Are you riding the Google AdSense wagon?