That strange internet-era compulsion of jumping back and forth between an endless array of browser tabs has spawned everything from satirical Onion coverage (” Accidentally Closing Browser Window with 23 Tabs Open Presents Rare Chance at New Life”) to scientific speculation about whether it’s an addictive, brain altering practice. But when Alex Groth and Kevin Jennison felt that same inexorable pull themselves about five years ago while studying in college, they decided to harness it to help others.

“Both he and I did some scientific research and we always had 100 tabs open on our computers,” Groth says only half-jokingly. So in 2011, the co-founders launched Tab For a Cause, a free browser extension that places two ads on each new tab you open-with part of the revenue they generate going to charity. Each time a new tab opens, users receive “Hearts” which become a shorthand currency: How you allocate them determines what each featured charity receives. The add-on is available for Chrome and FireFox. Here’s a video about how it works.

The extension allows users to customize their tabs with things like Google Calendar and news about the charities you’re helping support. Users can create groups to see their combined impact. At a time when being able to manage an obscene number of open tabs is something of a status symbol, there’s some deep gamification built-in: Users can achieve different levels of tabbing prowess, see how much they’ve raised, and how many people that has helped. The point, of course, is to continue to incentivize extra tabbing.

To date, the effort has raised nearly $300,000 for different organizations including Water.org, Conservation International, and Action Against Hunger. That’s counting donations from Goodblock, a free ad blocker that also lets users accrue Hearts for watching a daily curated ad. (Both operate under the roof of Groth and Jennison’s parent company, Gladly.)

In an effort to add more users, Tab For a Cause is running a Giving Tuesday campaign. From November 28 through November 30, the group will contribute an additional 25 cents to charity for each new person who joins. “It’s kind of a really intuitive sell,” Groth says. “You are spending all this time online anyway. You are looking at a ton of banner ads. Why not have some of it go to charity?”