Instant opinion app Thumb is seeing user engagement of almost 3.5 hours a month

Mobile question and answer service Thumb may now be more popular than Pinterest and Tumblr, at least in terms of the time users are spending on the service every month.

According to Thumb’s latest figures, the average user now spends 205 minutes per month on the opinion sharing service. Compare that to comScore’s latest research on social media use that showed the average Tumblr and Pinterest visitor spent 89 minutes a month on each of the service’s websites. While comScore’s numbers aren’t a perfect comparison because they exclude mobile use, they may mean Thumb’s users are just as engaged as those on the greatly buzzed about Pinterest, despite the fact that the app is still relatively unknown.

For those unfamiliar with Thumb, the service allows users to solicit feedback and opinions based on a picture and short question. It is backed with $5.5 million in capital from SoftBank, Draper Fisher Jurvetson, BlueRun Ventures and General Catalyst Partners, and originally launched under the name Opinionaided.

Voters can voice their opinion with a thumb up, a thumb down or a neutral thumb, and have the option to leave a comment if they desire. Users can also choose who they poll with their questions, querying just men, just women or a combination of the two, just their friends in the service or even people from their contacts.

When Thumb launched in July 2010 the company estimated users would get 10 opinions in two or three minutes, but today the average question gets about 70 responses and 10 comments. Thumb’s co-founder and CEO Dan Kurani, tells us about of a quarter of all responses include a comment.

Inside Mobile Apps put Thumb to the test by posting a query about a piece of art to my own moderately popular Twitter account. The Twitter post returned 11 responses in seven minutes and Thumb returned 67 votes and nine comments in the same amount of time, right in line with Kurani’s averages. For users who have fewer Twitter followers, Thumb is by the far the better choice for instant feedback and opinions.

Thumb’s responses were also more balanced, with a 60/40 split between positive and negative opinions on Thumb and 100 percent positive responses on Twitter. According to Kurani, Thumb helps eliminate the selection bias (where users only respond to questions they felt strongly about) by not allowing its users to skip questions.

Kurani declined to share the size of Thumb’s user base with us, but did reveal it’s three times larger now than it was in September. Thumb’s demographics are almost evenly split between men and women, but is beginning to trend slightly towards women as it grows. So far the service most popular with users between the ages of 18 to 34, which is to be expected for a startup based on a mobile app.

Although the original reason for creating the service was what Kurani calls utility questions (e.g. “I’m looking at these shoes, what do you think of them?”), the other surprise development is Thumb’s users are primarily using the service to make social connections based on their interests.

“The majority of questions that come in are social, like ‘do you like Green Day?’,” Kurani explains. “That’s a social question because unless they’re right there about to buy Green Day tickets, its likely they just want to see if other people who are using the product like Green Day.”

Interestingly enough, although Thumb is turning out to be social service, its growth isn’t being fueled what typically powers social networks — the organic connections between users as they invite their friends.

“We see enough [invitations] for organic growth to go up, but as the brand is becoming more ubiquitous we’re seeing growth through word of mouth and I think that’s partially leading to the uptick in our growth rate,” he says. “You don’t always want to go out to your entire social graph with some of these questions.”