Was? It's still going. And they've actually stepped it up a bit lately, as you can now see other people's Klout profiles via their giffgaff community profiles (but only if they've connected the two, of course).
A previous thread discussed klout. Some of us knew what klout was, some of us didn't know. Both groups tried to link klout to gg with varying degrees of success. While I didn't know what klout is, I tried and failed to link as per the instructions. Since May2015, there doesn't seem to have been any further decipherments or promotion of this tie in within gg