I wanted to post a thread later on it, but I guess I'm just going to explain this here.
We're displaying ads on the header for guests for several months now. I've never displayed any ads for members until now.
So why now?
The forum is growing within every day and we try to make the things we create for the forum as "high quality" as possible. We don't want to provide you something broken or anything which looks ugly.
I decided to purchase a lot of graphics for the site, which cost a lot of money. I'm talking about hundreds of dollars here.
I could just increase the price of upgrades, but I don't want to do that, because I still want to make them cheap, so everybody is able to afford them.
I've placed the ads for members on the footer, so they're not going to annoy you that much. I know, everyone hates ads.
Although, you're still able to use adblock. I have no problem with that.