I'm selling advertising space on my biggest website, Tau Online:
Tau Online is a fan-site for the wargaming hobby "Warhammer 40K". My site has over 8,200 members, and their ages range anywhere from teenagers to middle-aged adults.
Tau Online's website homepage has PR4, and the forum homepage has PR3. Other pages' PR vary from 0 to 3.
For a limited time only, I can offer you at least 100,000 advert impressions monthly, for just $25 per month. The adverts are 468x60 (you supply the images), and are in rotation at the bottom of all website pages and forum threads.
Payment will be via a PayPal subscription. I will accept payments per quarter (or longer time periods); a 10% discount will be given for paying like this.