Pinterest co-founder Paul Sciarra leaving company (updated)

Update: Sciarra, in a Pinterest blog post, confirmed his departure.

Is there trouble in Pinterest paradise?

Paul Sciarra (pictured, left), co-founder of digital pin-board sensation Pinterest, is said to be on his way out the door. Sciarra will be leaving the company as soon as next week, according to a report from Startup Grind, which said it confirmed the departure with several company insiders.

Pinterest, first launched in 2010, came out of Cold Brew Labs, a product shop started by Sciarra and college pal Ben Silbermann. The one-time experimental project has caught fire in recent months and could be worth as much as $500 million in a sale. Members use the site to “pin” products to collections called “boards,” an activity that’s become so popular that even President Obama is doing it.

Why would a co-founder get off a train that appears to be steamrolling ahead to Facebook-level fame and fortune? Details of Sciarra’s departure aren’t yet known, but we doubt they’re anywhere near as pretty as the site Sciarra helped to create.

Troubling though the departure may be, Sciarra’s exit will be a minor blip for the up-and-coming company that shows no signs of slowing down. In February, Pinterest, at 17.8 million unique visitors, was the third-highest-gaining web property in terms of unique visitors, according to comScore’s calculations.

Pinterest and Sciarra did not immediately respond to requests for comment.

Update: Sciarra, in a Pinterest blog post, confirmed his departure and said he accepted a position as Entrepreneur-in-Residence at Andreessen Horowitz. “After lots of reflection and plenty of discussion with Ben and others, I’ve decided that now is a good time for me to step down formally from day-to-day involvement,” he said. “Of course, I’ll continue to be there for the company: now, as an advisor, an owner, and — as always — a dedicated pinner.”