Netflix Inc shares soared 15 percent on Thursday as another round of strong quarterly results shelved any short-term worries about an overheated stock price or competition from powerhouses such as Inc.

The sharp rise in the shares came the day after Netflix reported a surge in fourth-quarter profit and said it had signed up another 3 million subscribers, surpassing the expectations of the company's own executives.

They did it again! JPMorgan analyst Imran Khan wrote in a note to investors. JPMorgan raised its price target on Netflix to $224.00 from $186.00 and said it deserves the premium its stock gets over others.

Still, there has been some wariness attached to Netflix since the stock has skyrocketed, reflecting concerns that the shares have outstripped the company's growth prospects. The stock rose 280 percent in 2010 and currently trades at about 45 times earnings, far richer than Google Inc, for instance, which trades at closer to a multiple of 18.

Investors have been quick to sell companies that don't surpass expectations by a wide margin in the current earnings season, as exhibited by network equipment maker F5 Networks, whose shares tumbled last week on a gloomy outlook.

Netflix avoided that, but a number of analysts still caution that the stock may have become rich.

Jefferies analyst Youssef Squali, for one, kept a hold rating on the shares even after the blow-out quarterly results, noting full valuation on relatively aggressive assumptions long-term, along with poor visibility into the company's international expansion plans and competition from Amazon and Google.

Citi analysts also maintained a hold/high risk rating on Netflix, but noted the company's momentum related to, among other things, the appeal of its streaming service through more connected devices like Apple Inc's Apple TV.

Netflix's bright quarterly results and outlook sparked its shares to gain $27.66 to $210.69 in afternoon trade on Thursday after rising to a multiyear high of $211.30 earlier in the session.

Netflix's fourth-quarter earnings and results demonstrate the kind of accelerating growth we think is necessary to drive additional upside in the stock price over the coming year, wrote Canaccord Genuity analysts.

Netflix, which is known for delivering its customers' movies and TV shows through the mail in bright red envelopes, is making headway bringing consumers streaming programing.

It subscriber base now stands at 20 million, meaning it added nearly 8 million subscribers in 2010, its best year yet.

Netflix's rise has stoked tension among entertainment, media and cable companies on concerns that consumers are dropping pricey cable packages in favor of services like Netflix.

Time Warner Cable Chief Executive Glenn Britt said on Thursday that most video customer losses were due to the slow economy and weak housing market. Like other cable executives, he raised doubts as to the sustainability of Netflix's business model.

Time Warner Chief Executive Jeffrey Bewkes has been a loud critic of Netflix's business plan, at one point comparing the company to a 200-pound chimp rather than the proverbial 800-pound gorilla.

Netflix will likely be on the minds of analysts and investors as media conglomerates like Time Warner, News Corp and Viacom report quarterly earnings next week.

(Reporting by Jennifer Saba; Editing by Lisa Von Ahn and John Wallace)