It may be too early to write off Rackspace Hosting's ( RAX) recent IPO as a disappointment. The IT hosting company headed to the public markets amid buzz that its shares would price at $17. They ended up pricing at $12.50, near the bottom of its proposed range, then falling as much as 20% below that price in its first day on the NYSE. Because Rackspace looked so promising at first, it was seen as a canary in the scary coal mine that the U.S. stock market has become this summer. So its initial plunge set off discussion about what happened. After Rackspace started trading, I wrote a column with my take: The company has seen profit margins deteriorate slowly but steadily over the past couple of years, and it had some outages that affected bloggers, who in turn directed a lot of publicity about the outages. Its valuation seemed a little rich for a turbulent market. Since then the stock has rebounded a bit, closing up last week to $10.69 (on Monday, it was off 7 cents). I received a few thoughtful emails, some from Rackspace clients saying they liked the company's service, and some suggesting my view was too bearish. Then I came across a report from Renaissance Capital, an investment research firm publishing some of its work on the site IPOHome.com, that offered an interesting counter-argument. Matt Therian, a research analyst at Renaissance, took a look at the 18 IPOs that used the Dutch auction process rather than the more traditional pricing method favored by Wall Street underwriters. In a Dutch auction, a pricing is set after taking all bids and determining the highest price at which the total offering can be sold.