Netflix, Inc. (NASDAQ:NFLX) shares are up another 22+ percent this morning after the company posted significant subscriber growth. The stock’s price has more than doubled in about six months, thanks to the last two positive earnings reports. However, investors may need to heed caution in the months ahead.


The streaming video service provider reported 3 million new streaming customers during the first quarter of 2013, including around 2 million streaming customers in the U.S. It added about the same amount of U.S. streaming customers in the previous quarter, although Forbes points out that the cost of customer acquisition has jumped significantly since then.

Netflix, Inc. (NASDAQ:NFLX) now pays about $7 more than in the previous quarter to acquire a customer. That means it takes one month of streaming revenue and three months of margin before Netflix even breaks even on its new customers.

In addition, there are signs that Netflix, Inc. (NASDAQ:NFLX) is looking for subscriber growth to slow down in the current quarter. Forbes contributor Mark Rogowsky ran the numbers, and according to his estimates, the company should see about 29.5 million subscribers paying by its June quarter. However, the company guided for only 28.9 million paying subscribers.

Of course this could mean that the company is simply being conservative in its estimates. Also the quarter ending in June may simply grow more slowly because of slower seasonal demand.

On the plus side, the company has begun to roll out higher-priced packages as analysts have predicted. The first addition to its plans is very basic and small, but it’s a start. For $12 per month (compared to the current standard $8 per month streaming package), Netflix subscribers can stream four videos through their accounts at the same time. With the lowest-priced package, they can only stream two videos at once.

However, Netflix, Inc. (NASDAQ:NFLX) said it’s predicting less than 1 percent of its streaming subscribers will even sign up for the new plan.