Forum monetization is something that is very hard for some people to do. Here are some tips on how to have your forum make more money.
Yes Adsense works great for forums. You will hear people that urn forums compliant that the Revenue per Thousand Visitors (RPM) is much lower than the RPM you earn with other websites and blogs. Your actual RPM with a web forum will be lower; however, you need to keep in mind that the reason for this is because the average visitor to a web forum may view multiple pages. Regular visitors to the forum may interact with 20 or more pages each day. With a blog a person does not tend to visit near as many pages. Although the RPM is lower, it is not because visitors to the forum are ad blind or do not like to click on the Adsense ads, it is only because they tend to view a lot more pages than a regular website visitor and this number will skew the RPM statistics.
Most people that are not earning much money with Adsense on their forums is because they do not get enough visitors. In order to ensure you get enough visitors you need to use quality forum software such as V-Bulletin, ensure you are constantly adding new and interesting content, and that the pages load fast. If you have a web forum that loads super slow then it will irritate your visitors and they will go elsewhere.
Most successful web forums are based around a specific niche. If you have specific niche then you may find success with an affiliate program that is related to the topic of your forum. If you have a forum that deals with snowshoeing then people who like to snowshoe or are interested in learning how to use snowshoes will be the primary visitors to your web forum. If you run integrate banners to an affiliate that sells stuff related to snowshoeing such as an ecommerce site that sells snowshoes and cold winter gear then you can earn a substantial profit if done properly.
Most people who integrate affiliate ads into their forum fail to earn much money because they either chose crappy companies to affiliate with, companies that have a low conversion rate, low traffic, or the wrong product.
If you are running a website forum about snowshoeing then you will not want to be a HostGator affiliate promoting hosting. Your conversion rate will be astronomically low. That is like having a Tea Party forum that focuses on the extreme right wing of politics and trying to sell Pro Obama bumper stickers. It is vital that you understand your audience and then market appropriately to them.
The number 1 reason people fail to make money with affiliate marketing on their website forum is because they do not have enough traffic. You need to be getting 1,000-3,000 visitors per day to your forum in order to make money. Yes you may get lucky but probably not. Affiliate marketing is a numbers game. You can reasonably estimate that a certain percentage of visitors will click on the ad and then an even smaller number will follow through by actually purchasing a product and earning you a commission. The percentage of visitors you need to send to an advertiser is the same regardless of how many visitors you get. If you average 1 sale for every 150 clicks to an advertiser then you will need to get 150 clicks from visitors. If you have little to no traffic coming to your forum then it may take you a year or more to get your first commission. On the other hand if you are getting 5,000 or more unique visitors each day then you can reasonably expect to earn at least 1 commission daily.