Our culture is peppered with idioms supporting preventative measures—an ounce of prevention, a stitch in time, etc. It's important to note that no one's grandmother ever told them, "Once you've overcome a problem, you can stop preventing it." This is also true in pay-per-click advertising, where preventing suspicious clicks, by using click fraud detection technology, means businesses use their budgets now.

Click fraud detection technology identifies and alerts companies to suspicious activity while it is happening, allowing paid search managers to stall ads running on keywords where the abuse is happening, preventing further budget loss. Look for technology that employs a learning algorithm or artificial intelligence. That way, the longer the technology works on that campaign, the more effective it becomes at identifying misuse. The faster it recognizes misuse, the more budget it can conserve.

Click fraud detection is a primary reason why Oneupweb's clients experience less click fraud than many marketplace estimates, which range anywhere from 10% to 15%. Most often, we can identify the activity, place the keywords on temporary hold, alert the search engine to the abuse and prevent the activity from ever appearing on an invoice. Only 10% of Oneupweb's b-to-b clients have been invoiced for suspicious click-through activity that caused Oneupweb to request credit from a search engine.

Furthermore, over the three years that Oneupweb has been managing b-to-b pay-per-click campaigns, the dollar value of suspicious clicks as a percentage of the total amount spent with search engines ranges between 0.13% and 0.39%. Small numbers overall, but still significant in terms of potential loss to a single business.

When any percentage of a company's budget is diverted to ineffective clicks, that money isn't working for the company. It isn't selling. It isn't generating leads. Even if the money is credited back after a search engine investigates a client's request, more than a month of opportunity has been lost and prospects have been missed. To understand the complete cost of click fraud, businesses should include an estimate for the lifetime value of those customers lost. From that perspective, a credit becomes meaningless. And the loss of those customers to competitors affects future markets share—wooing those customers back from competitors will be more expensive than securing their business today.

Shuman Ghosemajunder, Google's business product manager for trust and safety, has been proactively communicating with the marketplace on click fraud and what Google calls invalid clicks (most often explained as clicks coming from people inadvertently going back and forth repeatedly between an ad and a landing page). He's done his very best not to estimate what percentage of invalid clicks get charged to customers, but he does admit that it continues to happen in "negligible" amounts.

In addition to Ghosemajunder's comments, trends indicate that Google is getting better at identifying abuse before it hits an invoice. Of course Ask, MSN and Yahoo also require vigilance.

Vigilance on the search engine's part is just the start to any discussion on click fraud. Prevention is the key, by both search engines and campaign managers.

Leaving all the management up to the search engines is an expensive practice both in revenue and market share. Reaching prospects through search engines remains one of the most effective marketing strategies, and click fraud detection is a minor price to pay for its current value.

Lisa Wehr is the founder and president of Oneupweb (www.oneupweb.com), an integrated online marketing firm.