I'm reselling the week's worth of advertising I purchased for this forum in smaller chunks.
Here's some information from theymos:
Your visible ad text (ignoring link URLs, etc.) must be less than 150 characters in length, and it can only contain links: no other style. It will be prefixed with "Advertisement:". Ad text may not contain lies, misrepresentation, or inappropriate language. Ads may be rejected for other reasons.
There are 10 total ad slots which are randomly rotated. So one ad slot has a one in ten chance of appearing. One of the remaining slots has random factoids, and one links to the current ad auction.
Stats: On the 5th of November, 2011, there were about 124,000 views of topics. So one slot would have appeared around 12,400 times per day. The ad doesn't appear on topic pages with only one post, though, and it only appears for people using the default theme.
Info about the current ad slots:
https://bitcointalk.org/adrotate.php?adinfoTo start, the price is
2 BTC per
24 hour slot. I can guarantee that your ad will be displayed for at least 24 hours for each slot you buy, plus for however much time it takes for the next ad to be approved and changed by the forum administration.
The next slot available is:
AFTER 2011-11-21 20:00:00 UTC
