Twitter's Valentine's surprise: More funding!

Forget flowers and chocolate. Valley darling Twitter is going to have a really sweet Valentine's Day. The company announced Friday that it has added some more cash to its most recent round of funding, thanks to an infusion from Benchmark and Institutional Venture Partners.

The deal just closed on Thursday night, according to a post on Twitter's official blog. But the team at Twitter, which has not yet put forth a business model, hopes to make it clear that they weren't desperate for cash.

"We weren't actively seeking more funding because significant capital from last year's partnership with Bijan (Sabet) and his team at Spark (Capital) is still in the bank," the post by co-founder Biz Stone read. "Nevertheless, our strong growth attracted interest and we decided to accept a unique opportunity to make Twitter even stronger with a very attractive offer."

Financial terms weren't disclosed in the blog post. The Silicon Alley Insider said they've heard $35 million from Institutional Venture Partners. We're looking into this; we heard that the company's valuation, meanwhile, may be as high as $250 million.

But wait! It sounds like money's on the way, even though Twitter just keeps raising more venture capital. "We are now positioned extremely well to support the accelerating growth of our service, further enable the robust ecosystem sprouting up around Twitter, and yes, to begin building revenue-generating products," Stone's blog post read. "Throughout this year and beyond, our small team will grow much bigger to meet the challenges and opportunities ahead."

Twitter raised its third funding round, led by Spark Capital, last spring.

This post was updated at 11:33 a.m. PT.