I like the concept of weighting the ratings based on production numbers, but some games are lacking accurate data and I'm not sure how Pinside code could account for that element. Several observations come to mind here. Just because something is 'rare' (low production numbers) doesn't mean it is automatically a great game. I have played/restored several very low production games that didn't do a thing for me........artwork, or game play.
Those production numbers were often based on how well a game was selling, which should correlate to earnings/people playing the game/fun game, right? On the other end of the spectrum, not every higher production game has withstood the test of time with the current collector audience IMO. If you want to collect a certain rare/unpopular game, why would you want it to gain in the rankings/popularity anyway? It will inflate the price and make it harder to find. A really good example for me is Abra Ca Dabra. Five years ago that game was often maligned for its 'dark/evil' art package (though I have always loved it, along with Black Sabbath, etc.). Often hard to sell due to that aspect, the truth is, it has a great geometry and ruleset. (Team One even better ruleset, but can't deal with the artwork). Lately, I haven't seen an Abra come up at alllocally, just on Greed-Bay for 5-10 times what they were a few years ago.