Eager investors threw up their hands in frustration earlier this week when the Financial Times reported that Facebook's long-planned initial public offering would likely be delayed until late next year. Why the wait? Here, five theories:

1. Facebook is in no hurry to pocket the money
"An IPO is often meant to generate money, something the blockbuster social network doesn't seem to need," says Mobiledia at Forbes. Indeed, according to April Dembosky in the Financial Times, Mark Zuckerberg wants "to keep employees focused on product development rather than a payout."

2. Facebook wants to avoid the responsibilities of going public
There are advantages to staying private for a bit longer, says Lise Buyer, a consultant who advised Google when it went public. "You don't have to take investor phone calls or show up at investor conferences." That's why "many analysts advise against an IPO unless absolutely necessary," says Mobiledia. But eventually — probably sometime next year — Facebook will have to file public financial results to comply with government regulations affecting all companies with 500 shareholders.

3. Facebook is aping Google's strategy
According to Peter Thiel, a big investor in Facebook and a Silicon Valley notable, the company is following in Google's footsteps. The search giant delayed going public for half a dozen years, waiting until it dominated the search sector. "It was a good competitive strategy," he tells the Financial Times. "And it culturally orientated people toward long-term value and not quarterly numbers."

4. Facebook wants to keep employees around
"Silicon Valley's talent war might also be a factor in the timing of the Facebook IPO," says the Financial Times. It's likely that some employees are eager for the company to go public so they can cash out. But Zuckerberg is reportedly hoping to keep key talent around through summer 2012 "in order to complete certain product rollouts."

5. The market is just too unstable
The markets have been swinging violently thanks to Europe's sovereign debt crisis and the sputtering U.S. economy, says Don Reisinger at CNET. "Such volatility is making some companies wonder if it might be the wrong time to initiate an IPO."