idea for a webscale app

Spam is a problem on the Web.  More and more often robots will spam or even
take down a site if not controlled.  The CAPTCHA was invented to solve
this.  Most people agree that CAPTCHA's are annoying.

However, the question is why should you solve a CAPTCHA for every site you
sign in to?

Imagine a world were you only ever needed to solve one puzzle to be
verified as human.  Or one where every puzzle that you solved was added to
your credentials as a user.

Why not make an app that simply lets you login and lets you solve a
captcha.  For every one you solve it goes on the public record (open world
assumption).

Then when logging into a new site you need not be challenged again.

In fact this can be the part of your digital reputation and later on you
can tag more and more valuable achievements onto your online identity.

No longer do you have to start from zero on every site you log into.

You start to grow your digital footprint, and more and more reputation
items.  Who knows, one day you may be able to add your academic
achievements or qualifications to a list.

Some people have letters added to their name, maybe in the future the Web
can be a source and showcase of your achievements, both digital and human!