. I've created 8 identical markets; this one and 7 others. For each of them I'm purchasing different amounts of advertisements.

It's possible for people to figure out which are which by checking the market URL that the ad links to, but I politely request that you don't do so, or at least don't post it in the comments.

After the markets all close, I'll post a list of which markets had what ads purchased for them and how many traders they each got, and we can see whether the ads had any noticible impact.