It's a hot week for public debuts. Shares of two tech-related companies, CafePress and Millennial Media, gained in their initial public offerings Thursday.

Millennial (MM) more than doubled in early trading. It priced its initial public offering at $13 per share, the high end of its range. Shares opened on the New York Stock Exchange on Thursday at $25, and they quickly rose to $27.50 each. By the late afternoon, Millennial shares were trading at $24.27.

Founded in 2006, Millennial Media has emerged as a competitor to behemoth rivals Apple (AAPL, Fortune 500) and Google (GOOG, Fortune 500). Facebook, which has dominated in display advertising, has so far ignored the mobile ad sector -- though that may change soon. Facebook said last month that it would start expanding into mobile ads.

Like many other newly public startups, Millennial Media is not profitable. Its losses narrowed sharply last year as its sales increased. Millennial took a net loss of $287,000 in 2011 on sales of almost $104 million. In 2010, the company recorded a net loss of more than $7 million on sales of nearly $48 million.

CafePress (PRSS), which was founded in 1999, also began trading Thursday on the tech-heavy Nasdaq.

CafePress opened at $21.50 , but the stock was trading at $20.46 late in the session. The company, which was founded in 1999 and survived the early-2000s dot-com bust, prints custom designs on items like T-shirts and mugs.

It priced its IPO at $19 a share, above the $16 to $18 range it had set previously.

Unlike Millennial Media, CafePress made a profit last year. It netted $3.6 million on $175.5 million in sales. That's up from a $2.7 million profit and almost $128 million in revenue for 2010.

CafePress and Millennial are just two of 10 companies expected to go public this week. On Wednesday, organic food company Annie's (BNNY) closed 89% higher after pricing at the top of its range.

Two other companies that went public Wednesday also surged. Vocera Communications (VCRA), a maker of health care technology, closed 32% higher, and consumer finance company Regional Management (RM) finished the day up nearly 10%.

Investors appear to have a strong appetite for IPOs this year. According to the New York Stock Exchange, the average return for IPOs on their first day of trading this year is 15%.

Source :money.cnn.com