Moreover, I think we need a system to discourage retaliatory rating, although I recognise that that will involve more work for the site managers.
-- phinland

It's also not easy to settle on a fair system. Every automatized system will have its flaws, and they would inevitably get exploited by some, and/or favor one party over the other. In the end, sites relying heavily on ratings (eBay, etc.) all offer the possibility to appeal to Human arbitration, which is something modulargrid's staff might not want to spend time on - and I may not want to pay for their extra work.

Besides all that, I just bought @klodifokan 's Nutella Tsunami and it's great.