In August 1997, QSpace (now owned by Experian) was first to bring credit report data to the Web. The cost was $12 per report (see note 1), a price that has changed little over the ensuing 10 years.
Three years later, in October 2000, WorthKnowing.com introduced the concept of ad-supported (i.e., free) credit scores (see Online Banking Report, #66, article reprinted here). But the company failed to make it through the dot-com crash and ceased operations (note 2). Both QSpace and WorthKnowing earned OBR Best of the Web awards for their innovations.
It took seven years for the concept to reemerge, but now two Bay Area rivals are offering free credit bureau info in exchange for permission to present credit and other product offers. And just as I was about to finish this post yesterday, Quicken Loans introduced Quizzle, a personal finance/credit portal that also offers free credit bureau info (yesterday's post here).
Here are the players:
Credit Karma: This San Francisco-based startup, with backing from Prosper's Chris Larsen, is delivering an actual credit score computed by TransUnion, one of the three major U.S. credit bureaus. It does not precisely match the commonly used FICO score from Fair Isaac. And the scale is different, with a top score of 900 instead of 850. The credit score service is still in closed beta, but we'll see if we can get some invites from the company. Credit Karma will be presenting at our FINOVATE Startup conference April 29 in San Francisco, if you want to meet the team behind this new service. 
Credit.com: Another San Francisco company, but one that dates back to 1995, recently launched a similar system, called the Credit Report Card. Credit.com CEO, Adam Levine, presented his other company, Identity Theft 911, at our inaugural FINOVATE conference last fall in NYC (video here). Credit.com provides a full evaluation of your actual TransUnion credit report and assigns letter grades to five different components of the overall score (see third screenshot below). The score is shown on a chart at the top that appears to top out at 850. The report is extremely well done. Like Credit Karma, the company earns fees from targeted offers. In our case, we were given a choice of applying for two Citibank cards. 
Quizzle powered by Quicken Loans: Quizzle's business model is completely different because it's run by a financial institution instead of a lead generation site. The idea here is to get customers and prospective customers to use Quizzle frequently so that when the time comes for a new mortgage, the user remembers to apply at Quicken Loans. See yesterday's post for a complete overview.
Credit Karma homepage (15 Feb. 2008)
Credit.com Credit Report Card homepage (15 Feb 2008)
Credit.com Credit Report Card (top portion, detailed analysis of each section not shown)
Note:
1. QSpace charged $12 for the first credit report, then $5 each to reorder. Data was from Experian (see Online Banking Report #28).
2. TransUnion now owns the WorthKnowing domain name.