BlueKai, which runs a marketplace where advertisers can buy data about online shoppers, has raised $10.5 million in a second round of funding.

The Bellevue, Wash. startup allows shopping sites that have collected data about your interests and activities to sell that information to advertisers. Done right, that kind of smart advertising could probably deliver much higher returns than traditional ads. In fact, BlueKai says it can provide three times the response rate of a normal campaign. It also says “half of the top 20 video and ad networks” have purchased data through BlueKai’s marketplace.

This is all supposed to occur in a very privacy-friendly manner; the company says it enables “polite marketing.” Consumers, understandably, may not take these claims very seriously, but at least BlueKai also offers a registry where you can see what kind of information is available about you and opt out of the process.

The new round was led by Battery Ventures. Redpoint Ventures, who led BlueKai’s $3.2 million first round, also participated.

VentureBeat's mission is to be a digital town square for technical decision-makers to gain knowledge about transformative enterprise technology and transact. Discover our Briefings.