Klout is a very clever way to gather data from users without giving much in return. Users only get a vanity number, which might be useful if you want to monetize your online persona or brand. But that’s about all the benefit you get from Klout.
This vanity number can obviously only be calculated if you give Klout access to all your social profiles the retrieve follower data and engagement numbers. Giving access to most social accounts means all personal data is gathered in a single place: on Klout. This is very compelling for companies wanting to target users to maximize advertising impact and therefore ad revenue.
One of the especially clever ways is to have you save your birthday, postal address and country on Klout to get perks. Stuff they get from third parties who in return have an interest to get in front of you. Win-win? Yes. But also win-win-lose, to be more precise. Because you lose.
This data you enter to get your hands on those perks is data, which is normally not required for most sites on the web (shopping excluded). That means you don’t store it in your social profiles. By giving away perks they manage to enrich their data they gathered about you with important information to cross-reference your data much more precisely.
Essentially they pay a little by giving perks to users to have them drop their pants. Pretty bad deal if you ask me.