It provides single sign on(SSO) in a decentralized, private manner. For instance you see 'login with facebook/google' buttons all over the web, but that gives

It provides single sign on(SSO) in a decentralized, private manner. For instance you see 'login with facebook/google' buttons all over the web, but that gives FB/Google all sorts of fabulous information about you, and has zero privacy. With Spresso, you can offer the same sort of thing, an identity you can share across many different websites(provided they support spresso), without sharing any information anywhere.