Alex Taub and Michael Schonfeld had their first taste of viral success two years ago when they launched Most Valuable Follower. As the name implies, it did one simple thing: help users find their most influential Twitter followers.
Some 50,000 people tried out the service in its first week, and more might have done so if it didn't crash for hours early on from all the demand. That success was short-lived, though: A month or so after launch, Taub and Schonfeld joined Dwolla, a payment startup, and decided to shut their project down.
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While they were willing to put the service to rest, at least one group of users continued to ask for them to bring it back every few months: brands.
"Brands started reaching out asking us to turn it back on," Taub recalls. Many of these brands noted the abundance of tools to schedule posts and track conversations, but then added, "there's really no good tool to find the people to engage with on Twitter."
A few months shy of their two-year anniversary at Dwolla, Taub and Schonfeld decided to leave the startup, return to the Most Valuable Follower project and turn it into a proper company. The end result is SocialRank, which aims to help brands and other users pinpoint the people they should try to get to retweet or engage with their content online.
Social Rank refines the Most Valuable Follower feature with a number of new data points: how often a user tweets and favorites your tweets, whether he's verified, how many people he follows. It also lets users see which followers engage with you the most, and creates a Best Follower list, which is a combination of your most engaged and most valuable followers from the previous 30 days.

An endorsement from any one of your followers may not be as valuable as that of celebrity like Beyonce, but together, they could prove very useful for brands. Taub refers to this phenomenon as "endorsements for the 99%."
The startup has signed up a few notable partners at launch including Harry's, GoPro and Spotify, who will use the tool to find their best followers and then reward them with promotions or giveaways. Spotify will offer one of its top followers a free month of its premium service; Harry's will reward one of its followers with a haircut and shave at its barbershop.
The launch comes amid rumors that Klout, a service that originally helped pinpoint influencers, is close to being acquired by Lithium Technologies, a customer engagement service, for $100 million or more.
Taub admits that there are some similarities between SocialRank and Klout, but adds: "This space is still not really perfected. There is still a big opportunity around brands and individuals."
The startup will offer a free version of SocialRank, which provides monthly reports of your 10 best followers, and a premium version for $25/month that provides deeper and more frequent reports of your followers.
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