• by Laurie Sullivan  @lauriesullivan, November 21, 2010

StumbleUpon released an Android app recently. One of the most popular tools has become the app discovery feature where a site visitor picks a few categories to find apps. More than one million apps have been stumbled on, according to the company. The success is no surprise for some execs.

The social site recently joined the ranks of media communities directing streams of consumer traffic to Web site home and landing pages. At least that's the case for Mint.com.

Acquired last year by Intuit, the personal finance service targets the tech-savvy professional between ages 25 and 40 with above-average income who is heavily into social media.

Paid search had been too expensive, so Mint.com began working with StumbleUpon in 2008, contributing articles and videos for community members to stumble on. The company built a brand in the StumbleUpon community that drives traffic to its Web site, according to Stew Langille, vice president of marketing at Mint.com.

Langille says both paid and organic content placed on StumbleUpon provides a far better return on investment (ROI), compared with paid search, display or any other type of advertising. Mint.com averages 180,000 monthly visits from StumbleUpon. "We had a specific goal to target cost per acquisition," he says. "The advertising drives people on StumbleUpon to view organic content, which we want the community to pick up and share."

To target interest groups through StumbleUpon Ads, Mint.com created a campaign targeting anyone who indicated an interest in weddings to promote its Wedding Budget Checklist page that now receives more than 80% positive ratings from StumbleUpon users, and averages more than 5,000 page views per month since April.

The company also had success promoting its home page to females age 18 to 25 in the U.S. who are interested in self improvement, averaging nearly 15,000 additional page views each month for the past seven.

With the ability to directly target specific audiences based on their interests, Mint.com's use of StumbleUpon Ads led them to develop unique Web content to reach key audience categories aside from financial. The results are the lowest cost per new user and most cost-effective conversion rates of any paid advertising efforts. StumbleUpon content drives traffic to Mint.com's Web site where about 2.5% of visitors sign up.