I got all my friends to go on it and spent lots of time ranking people myself.
I also started things off with "fake" tests so that people had other people to rank at the beginning, otherwise folks would just see a dead app and drop off.
It was a really big moment 9 months in when someone's test completed entirely without me ranking. It was a lot of work & I'm really glad to be at a point now where I get to watch people rank each other without me.