It was a big week for initial public offerings as shares of 10 separate companies opened for trading. If you're thinking about investing in any of these recent IPOs it's important to first weigh the risks. It is easy to get caught up in the hype and buy the IPO rather than the company, which often ends in disappointment. After sifting through the facts and filings, here are my top picks from this week's stock debuts.

Millennial Media (NYSE: MM) doubled out of the gate on Thursday after pricing shares at $13 a pop. The company currently claims almost 17% of the mobile ad market, which makes it the second largest mobile ad firm in the U.S. behind Google (Nasdaq: GOOG). With mobile ad revenue in this country set to reach $2.6 billion this year according to eMarketer, Millennial is in the right market in terms of growth potential.

I think the company's lead position should help it grow in tandem with the booming mobile market. More than ever, people are buying products on their phones or using smartphones for price discovery. This mobile commerce trend will only get stronger as data plans and mobile platforms improve. Now consider that Millennial's mobile solutions already work across 7,000 different devices to deliver ads to more than 200 million global cell phone users.

CafePress (Nasdaq: PRSS) priced its IPO at $19 a share, which was higher than the expected range of $16 to $18. However, that didn't damper demand, because the stock opened just above $21 a share on Thursday before falling back to just above its offering price. The print-on-demand website shipped over 3.5 million orders last year, with revenue increasing 31% from the year prior. CafePress should continue to benefit from the rapid growth in e-commerce.

However, there are significant risks. For one thing, players such as Vistaprint (Nasdaq: VPRT) are a credible a threat to CafePress. Vistaprint tends to process larger transactions compared to CafePress, which primarily focuses on small quantity orders. Despite these concerns, I think CafePress' competitive advantage is its ability to crowd-source content from millions of designers. Meanwhile, Vistaprint's customers have to craft their own designs using the company's Internet-based creation software.

Annie's (Nasdaq: BNNY) continued to soar after its IPO on Wednesday. Shares were priced at $19 on the open and have close to doubled. It's always a good sign when a company puts money from its IPO to good use. In Annie's case, it'll use a portion of the proceeds to pay down debt.

Annie's brand has a strong following, despite having just four product categories to its name. And I wouldn't be surprised to see the company beef up its product lines as the year progresses. Annie's is riding the health food wave all the way to the bank. Last year, the company's revenue climbed 23% to more than $117 million. Consumers are willing to pay more for healthier products like Annie's, which improves profit margins. I think this stock will continue to surprise investors going forward.  

Takeaway
With each of these stocks' respective industries slated for significant growth, I expect Millennial Media, CafePress, and Annie's to all be strong performers in the years ahead. To avoid missing out on a profitable opportunity, add these stocks to My Watchlist, so you can track and monitor their progress.