Can you expand, a bit?

Arbitration can be of a lower standard. The arbitrator will probably be a lawyer, but not a judge. And standards of evidence can be much lower.

I doubt that there are many arbitration companies siding with someone just to get repeat business. That might depend on the scale of business though. For two small businesses, I can't see how it would be a big deal. If a company the size of IBM nominates an arbitrator, I might be suspicious.