How much traffic would a forum need to recieve before people will be willing to pay for a banner ad? There are plenty of advertisers in my niche, and the top 3 overture bids are all around $3.50 to give you an idea of the market. How many unique visits per day, how many visits, hits, etc?
You can sell spots no matter how much traffic you get, but the more traffic you get, the more advertisers will pay. I've sold ad space for $5 a month on a board that got 30 uniques a day. As the site grew, we gradually increased prices. If you have or can get some type of auction script, you can let advertisers bid for the next months banner slot. Just remember that its your site, and its worth what you say its worth. Its up to them to decide if they agree with you. Showing traffic numbers just makes it easier for them to decide if they agree or not.
Here's a tip, when trying to sell the ad space, don't talk about uniques per DAY... instead talk about MONTHLY figures. When you say "I have 200 visitors per day" it sounds ok but not THAT impressive. When you say "over 6000 visitors per month" it sounds way better. Just imagine a brick and mortar business with 6000 visitors a day! Pitch it this way and you're likely to impress your advertisers more. I'd say once you have at least 100 uniques per day you would be able to approach people advertise on your website... especially if it's a niche market.
For a site that's been up about a month now, the first two weeks I was averaging about 40 uniques / day. Week after, about 70. Today, 123 uniques, this is so exciting for me! So if that keeps up, what do you think would be reasonable to charge for something like a banner that shows on every page, every view. Thanks. Oh, and it is very niche.
It kind of depends on the niche. Contact someone you think might advertise with you and ask them what they'd pay. Be honest. Tell them it's your first site and that you have no idea what to charge. It landed me a $2000/yr advertiser on a very specific gaming forum. Could I have gotten more? Probably. Especially after the first few months, but it was a good start. Another option would be to join an affiliate program and place affiliate banners on your page along with the google ads. Check out commission junction, linkshare, or some other affiliate conglomerate.
Is there an exchange that you need to use to sell banner space? If so, will they create the banner for you.
As always, ask Google when you're in doubt. Yes, depending on the affiliate. Google typically only prohibits other contextual ads to share the page with them. Non contextual ads are probably ok. This means you can have G parse the page and serve relevent ads or Y parse the page and provide relevent ads, but not both. If one ad is a static, non-contextual ad, then you only have the one contextual ad (g), and that is probably ok. This is part of the popularity of the chikita minimalls. They can be set in a non-contextual mode and thus can reside next to adsense ads without violating Google's TOS. As always, ask Google when you're in doubt.