Twitter’s Elizabeth Weil Joins Andreessen As Partner, Will Set Her Sights On Social

Andreessen Horowitz continues building its arsenal. Days after the announcement that the firm had invested $15 million in innovative hip hop annotations startup Rap Genius, we learn that it’s hired Elizabeth Weil away from Twitter.

Weil was a marketing executive at Twitter, and prior to that worked at another VC firm, Institutional Venture Partners, where she focused on investments in Internet and digital media. Before IVP, Weil was an investment analyst at Menlo Ventures.

In addition to working 80-hour weeks for Twitter, Weil also runs the digitally focused Paperwheel Press out of her garage, handmaking “Welcome” notes to new Twitter employees among other things. She and her husband, Twitter director of revenue product Kevin Weil, are also avid marathon runners.

Weil apparently wore a few hats during her three years at Twitter (her Twitter bio lists “Design and Culture” and she also had a stint in Corporate Development) and we as of yet have no word on what exact projects she’ll be working on at Andreessen.

Both Andreessen and Weil confirm to us that she will be joining their Market Development team, which helps Andreessen portfolio companies with business development and marketing strategies. She will be working closely with A16z Market Development Partner Mark Cranney and will be focused Andreesen’s social endeavors, but will not be charge of social investments.

The breakthrough VC also recently scored with another startuppy hire: Foursquare dynamo Tristan Walker as EIR.