MSPmentor’s SaaS 20 Stock Index, which tracks the software as a service industry, slid 1.75 percent for the week ended June 20, 2008. But that’s not so bad, considering the Dow slipped 4 percent on the week and hit a 3-month low.

Of our 20 index members, only Amazon.com (AMZN, up 2.44%) and Taleo Corp. (TLEO, up 6.07%) posted sharp gains on the week. The index’s biggest weekly losers were Constant Contact (CTCT, down 6.85%) and Salary.com (SLRY, down 10.92%). The overall index (containing these 20 companies) currently stands at 859.98, down 14% from a starting value of 1,000.00 on January 1, 2008.

Here’s more about our weekly winners and losers.

Weekly Winners

Taleo Corp. (TLEO, up 6.07% on the week), which specializes in on-demand HR recruiting solutions, sounds downright bullish about its SaaS strategy. The company on June 18 raised its full-year revenue guidance and reaffirmed its Q2 forecast, according to the Associated Press:

Taleo’s momentum is noteworthy for several reasons. Roughly 31 percent of CEOs expect to make job cuts this year, according to this survey. Yet demand for Taleo’s SaaS-driven HR solutions remains strong. That’s impressive.

Meanwhile, Amazon.com (AMZN, up 2.44% on the week) continued to push forward with its on-demand strategy. The latest move involves Red Hat adding offering its Jboss middleware to Amazon’s Elastic Compute Cloud (EC2).

Amazon’s EC2 and S3 (Simple Storage Service) are emerging platforms that customers and MSPs can potentially plug into. Red Hat already offers Linux in the EC2 cloud, and the Jboss move further solidifies the growing role of open source in the SaaS industry.

Weekly Losers

Constant Contact (CTCT, down 6.85%) and Salary.com (SLRY, down 10.92%) were among this week’s biggest drag on our index.

Constant Contact’s one-week dip appears to be tied to profit taking; investors have seen the stock climb steadily since mid-May. The company specializes in one-demand email marketing services, and now serves more than 200,000 small businesses.

Meanwhile, Salary.com is struggling to restore investor faith in the company. Salary.com develops on-demand HR software that focuses on people, pay and performance. Ever since announcing disappointing quarterly results in mid-May, Salary.com has been working overtime to describe its plans for growth. But a May 20 strategic plan from the company apparently didn’t impress investors.

Looking Ahead (At Dell)

We’re continue to provide a weekly index recap, but we’re also expanding our daily coverage of all the index members. For instance, I got a tip that Dell is working on the next big step in its managed services strategy. And I’ve already got the scoop. I will be posting details on Monday, June 23.