Although not yet a household name, online lead generation was by far the fastest growing category of online ad spending in 2006, with a reported 71 percent year-over-year growth. Marketers are increasingly adopting this growing medium because it provides something search and the other more publicized vehicles do not: consumers' explicit permission to be added to your database and contacted for future marketing purposes.

Much like the "Web 2.0" movement, we're seeing a Lead Gen 2.0 that is more transparent than the lead generation of the past, ultimately giving buyers and sellers more control over their businesses and profits. Where in the past we've seen large, single-vertical aggregators that take the majority of the profits from a lead transfer, we are now seeing the emergence of smaller, more efficient lead marketplaces that serve multiple verticals.

Choosing an online lead generation provider can be a daunting task -- as you should not only evaluate the company's performance, but also if its methods and tactics are in line with your values as a reputable brand. While the previous article, "5 Questions to Ask Your Online Lead Generation Provider" was very helpful, here are my "6 qualities to insist on before engaging your lead generation provider...."

Online lead generation is capable of being a hugely scalable channel, with an ROI that makes perfect sense to an advertiser. Conversely, it is also capable of being a major money pit! Other columnists have previously pointed this out and have provided insight on how to avoid the latter by paying close attention to the placement and structure of the advertisement. While these two components of the ad are vital, I am going to focus on the back end -- what must happen after the lead is generated.

Not all leads are created equal. To illustrate this point, which lead generation program is more appealing? Would you prefer 1,000 anonymous email addresses where you eventually determine only ten to be good prospects? Or would you like one that delivers 100 leads, each of whom is an ideal prospect? The answer is obvious, but the trick is how to find those 100 prospects without wasting time sorting through thousands of anonymous and irrelevant respondents.

People are greedy. Oh sure, sometimes we break from the mold and have our altruistic moments, but at the core of our being, we love to receive. And in the spirit of greed, you can expect Web 3.0 to be adding an additional twist: revenue sharing. With the boom of user-generated content, most users were just happy to get a voice. However, the industry of UGC is maturing, and enough competition between venues has arisen that a new factor has been thrown into the mix: revenue-split models.

With a reported 71% jump in year-over-year revenue, the explosive growth of lead generation means it's one of the hottest sectors in online advertising in 2006. As major brands continue to enter the market in 2007, it's vital to be able to distinguish between top providers who will deliver a quality program -- and lower quality players who will waste time and marketing dollars. To aid in this effort, I've assembled five imperative questions to ask your current or potential provider -- and the answers you need to hear.

The current stampede to online lead generation is understandable, given that lead-gen and related activities like co-registration are the fastest growing segment of all Internet advertising spending, according to the Internet Advertising Bureau. Nothing else even comes close. For now, let's focus on co-registration, which can be a golden goose for many Web sites and advertisers.