The goal of gamification is to make a non-game task more engaging by introducing game-like elements. Gamification is still a new field but it has had some key successes, such as Foldit.
How could gamification contribute to technological unemployment? Well if you can make certain jobs fun and game-like enough, then people on the internet might do them for free. Or at least for far lower pay.
Imagine a company that is trying to keep costs low. First they might automate as many of their tasks as possible. Then they could take the few remaining tasks that still require human intelligence and gamify them. The company gets free or cheap labor, and people on the internet get to play a fun game. Everybody wins… except for the people who are now out of a job.
It remains to be seen whether gamification can be pushed this far, but I suspect it could. I imagine with the right designer you could turn almost any boring information task into a “game” that some people on the internet might obsess over and play for free.