BookBub, a daily deal site for e-books, announced it has raised $3.8 million in Series A funding, the first external capital secured by the company. The investors include NextView Ventures, Founder Collective, Avalon Ventures, and Bloomberg Beta.

The Cambridge, Mass.-based company has, according to BookBub, tripled in size since early last year, and now has nearly three million members (the startup announced it reached the two million member milestone in early December 2013).

BookBub puts together a daily e-mail blast that offers limited-time deals on free or deeply-discounted e-books, and, since it was launched in 2012 by Josh Schanker and Nicholas Ciarelli, has featured more than 10,000 e-book deals on titles from the Big Five publishers, mid-sized and smaller publishers, and independent authors.

“Since starting BookBub, our dual goals have always been to help readers discover great books and to provide publishers and authors an effective way to get their books discovered,” said Schanker. “A daily e-mail featuring deals on e-books is part of that mission, but we believe it’s just the beginning for BookBub, so we’ve raised money to widen our scope.”

The funding, per BookBub, will be used for growing its team "more rapidly," expanding into international territories, and launching additional products.