Last month, Google announced Google Capital, an investment fund for growth-stage businesses. This is for Google to invest in established companies as opposed to those just getting off the ground, which is what Google Ventures is for.

While the Google Capital investments have been happening for over a year, it was only in February that Google announced the fund and its actual name. With the announcement came a roster of three businesses that Google Capital had so far invested in: SurveyMonkey, LendingClub and Renaissance Learning.

Now, the fund has reportedly made its fourth investment in Auction.com. According to to TechCrunch, Google Capital made a $50 million investment in the real estate marketplace, and a rep from Google’s fund will join its board of directors, while another will serve as a board observer.

Auction.com has been repeatedly described as an eBay for real estate, as buyers bid on real estate, and actually initiate transactions online. TechCrunch quotes David Lawee, one of the partners leading Google Capital, as saying:

“Auction.com has quietly built one of the largest marketplaces on the web. We think Auction.com can fundamentally change how real estate, and particularly commercial real estate, can be bought and sold, leveling the playing field for smaller investors.”

The money will reportedly be used for product expansion, mobile development and sales/marketing.

Product expansion and mobile development were apparently on SurveyMonkey’s list of post-funding priorities as well. Since the Google Capital announcement (though the investment was made last year), that company has launched a new mobile app.

Image via Auction.com