it's fuelled entirely by reddit as a joke.

Reddit has a way of tipping people with bitcoins for posts

    /u/bitcoinbot 0.015BTC verify

people saw these public tips, kind of an alternative to reddit gold, so it entered the consciousness of the community. dogechain was born because, more or less, it was pretty funny to drop this on someone:

    /u/dogecoinbot 3000 doge verify

    dogecoinbot:
    Verified.

Sort of playing on the hopes of redditors to get rewarded for a post (ala reddit silver)

It's a pretty cute joke. Lots of people started following the leader and bang. Demand.