Banner advertising can be very effective

Since we've already discussed how you would encourage users to click on the ads, let's go over how you manage to sell the ads in the first place. Getting users to click on your banner ads requires that you place the right message or image in front of them at the right time - which is whenever they are on the web site while your ad appears there.
If your goal is to sell banner ad space on your web site, your job is no less difficult. You need to ensure optimal placement for your advertisers, which means striking a balance between the user experience and the advertiser experience. This can be difficult because, while your advertisers will happily tell you exactly where on a page they want their banners to appear, your users won't contact you to say they don't like the ads there. They will simply start going to other web sites.
Another point to consider is size. Larger ads perform better for advertisers, so you should seek ways of designing your pages so that they can accommodate these larger ad sizes. Don't be afraid to offer smaller sizes; just be thoughtful about where you place them and how you price their value relative to your larger, more prominent ads. Often, web sites throw these into banner ad deals at no charge for advertiser willing to purchase their more expensive ad slots.
When selling banners, it's important to be realistic. Always be honest with potential advertisers about your volume of traffic. Trying to impress them with inflated numbers will backfire when their ads fail to perform. Unless you have millions of users on your site every day, no one is likely to pay your $10,000 per month for ad space. Given how track-able everything is today, you'll be better served by starting out with modest ad rates for the first few advertisers who pony up. You should watch their results and see if you can use their success to increase rates slightly for a new advertiser. Using Google AdSense is a great way not only to monetize your site but also to define ad spaces, test them for effectiveness, and track what ECPM rates you could start with (ECPM measures the effective cost per each thousand page views). All this information will be provided in the reporting system used, such as the one provided with the Google AdSence platform.
Rarely do advertisers talk and compare notes on ad rates, so this is a legitimate route to increase your yield from these spaces over time. Just be sure that you can justify the increase if you are asked about them. Although advertisers rarely share this information, it does happen. For that reason, you should also have a plan in mind for advertisers who started out with you at a lower rate. Keep them at their lower rate until you see revenues increase from other advertisers. Then you might want to approach them and offer a locked in rate for the next six months or so, politely explaining that as traffic has increased on your site, so has demand for ad space, driving your ad rates higher. Give them the option to renew at a new rate after the extended grace period. Another option might be  to transition them to smaller ad units (or even to text links) for their current ad rates. the main point here is that you plan for the changeover and communicate with them. Upsetting advertisers is not a good way to keep the ad dollars flowing.
Banner advertising can be a very effective way to deliver traffic to your web site. Given that the nature of the ads is highly visual, you can also ensure that users are pre-qualified before they even hit your site, helping your efforts to convert. Like many areas of online marketing, banner advertising is best served with a big side order of testing.