– Connie Loizos is a contributor for PE Hub, a Thomson Reuters publication. This article originally appeared here. –

“I don’t think Facebook has peaked,” said Michael Birch, absently piling his trademark curtain of brown hair atop his head. “The point of saturation is often a lot further out” than many people assume, he added. “But what goes up must come down.”

We are sitting in his San Francisco offices and Birch, best known for selling his three-year-old social networking startup Bebo to America Online for a stunning $850 million in cash, is sharing some thoughts about the current crop of social networking darlings — and whether we’re in a bubble.

Birch has certainly had time to form some opinions. Months after Bebo’s 2008 sale, he found himself on the operating table, undergoing open-heart surgery for a leaky heart valve. The experience rattled Birch and afterward, he committed to permanently change his work-life balance, sticking mostly to angel investing to maintain his ties and perspective. He has since helped to seed fund 30 startups, including Mixpanel in San Francisco and London-based Onalytica, both of which offer their customers analytics tools to improve their market research.

Still, Birch tells me he “ducked out” out of angel investing at the end of last year. “I do think there’s a bit of a bubble – though I don’t like that word.” Soaring valuations simply made investing in very early-stage startups “a bit pointless,” he says.