See my previous response - AdSense not necessarily a good choice for forums. Particularly tech forums, I would think.

- Higher instance of ad blocker technology

- They're not there to click ads, they're there to discuss.

- (unrelated to CTR but) UGC issues and AdSense compliance.

I am sure there are probably some forums that have a decent CTR with AdSense, but honestly I never heard of one. Ever. And tech people particularly are into avoiding ads.

If bottom line you're making money with it, and you're not worried about anyone posting anything that could cost you your AdSense account, then don't worry about the CTR, I would say.

So what would you recommend as opposed to adsense?

I tried with peerfly, it was terrible.

Dunno; never tried to monetize a forum before (other than with subscriptions) If it's tech, maybe affiliate ads? Amazon tech products?

Generally I do this: 728x90 at the top, 728x90 after the last post on a page, and a 300x250 between the first and second post on the page (not shown to members though). CTRs are just bad in forums though due to their nature.

On topic books from amazon through an affiliate banner works decent. Adsense as such never got it to work.

Forums need a lot of moderation work, you cannot install and forget.

I really think you should try to work a 300x250 size in there somewhere, it can work well. It's worth testing anyway...

Its all about building a sense of community in your forum, then people will want to use your affiliate links, and more embarassingly make potentially invalid adsense clicks to support you.

IMO the ads are in the best locations possible and not too obtrusive (one at top, one in the middle, one towards the footer). Using 768x90.

A. Who clicks on ads?
Forums have several sets of users. I won't get into the different kinds of forum site visitors but will focus on ad clickers. In my opinion these are the ad clickers:

1. Newbs who discover they need a certain product and see an ad for that product so they click on the ad.

2. Site visitors who are seeking specific product information then see a relevant ad for that product.

B. How many ads should you place in a forum?
I think just two. Ads on top, below the navigation but before the actual content can get a decent click through rate. But ads below the content can also do well in a forum. Similar to the performance of affiliate ads. After raeding the content a site visitor may think , "Holy crap! My life/business/hobby is not the best unless I get one of those Acme Doohickys!" Ad Content with info about Acme Dohickys gets clicked.

C. Is this a money topic?
A topic doesn't have to be about Mesothelioma to be money. It just has to have a first to second degree focus on products. Are there products involved? Downloads? Trials?

D. Expert forums do not sell Acme products
Experts don't need products. They DIY or already have it. I said it before and I'll say it again: The only clicking experts do is on their keyboards, never on ads. Newbies buy products!

E. Inventory management
Too many ad spots can cause crap ads to fill the excess inventory.

I ran a niche forum for a while and made few observations with Adwords. Members complained about aggressive ad placement. I setup Vbulletin to provide a pretty conservative ad placement for logged in users. Consider that logged in users probably aren't as willing to click on ads (IMO).

What I suspect for you since you are a tech forum is that a significant amount of traffic comes from searches. I had similar experience. I used much more aggressive "in post" ads for users that aren't logged in. These ads turn more of a profit since they rely on the incoming visitors from search engines looking for something in particular.

Finally, you might have to do some leg work to up your monetization. I had much more success on my forum establishing a membership system, pay to play for business forum members. Basically business members paid for a higher level membership and got the ok to talk about their services on the forum, even a vendor specific forum. Take it another step you could probably sell them advertising space directly. You likely have a lot of niche business members on your forum already, offer fair rates and you'll likely get some takers. A great way to do this is to sign up for double click for publishers and you can seamlessly run your own banners and adsense in the same ad spaces.

How to Raise AdSense Earnings in a Forum?

Raise traffic..

particleman, very good suggestions, thanks!

Raise traffic..

That's also a good point. Any specific suggestions on things to do to improve traffic to a forum?

Any specific suggestions on things to do to improve traffic to a forum?

Well yes, but not on a very public forum....

Any specific suggestions on things to do to improve traffic to a forum?

It bugs me on fishing forums when members don't talk about where they went fishing. There are NO secret fishing spots. None. Similarly, there are FEW secrets for how to promote a forum. There are plugins, mods and hacks that do most of the work.

So here goes a partial list...

1. Meta descriptions might not help you rank but they WILL help raise clickthroughs from the SERPs.

Use a dynamic meta description that takes the first sentence or two from a thread and appends it to the topic title so the meta description is like Topic Title + words from topic. Be sure to have If/Else expressions that will pull the forum description for main forum sections.

2. Hack the software so that the topic title becomes the Title Tag.

3. Remove irrelevant links from the forum view template, links like links to a member's profile.

4. Build links from relevant sites to the different forum topics

5. Use appropriate social media (if your users are there) to engage them there and encourage them to bring their friends.

6. Make it easy to refer a friend with social media and tell a friend chiclets.

7. Make the topic title become an H1

That's a start...

[edited by: martinibuster at 1:22 pm (utc) on Nov 13, 2013]

1. Place ads in a boxed area similar to those which user posts are in.

2. Randomly change the size of the above ad.

3. A/B test the above - sometimes text only ads do best here.

4. Do not display signatures to guests/bots in order to help target better.

5. Show a minimal number of Adsense ads to logged in users.

6. Implement Adsense relevancy tags.

7. Since users can do things (on some forums) such as hotlinking large photos from external resources, page load speed can be critical. Implement async Adsense tags.

I thought I had optimized my ads very well until several months ago, after I forced the ad unit after first post as first ad on two tech forums, AdSense revenue almost doubled.

Blend your ads with posts instead of a separate block.

To find the best placement for your forums, you have to test by yourself, for example,

Place ads after 1st and 2nd posts, even 3rd post, they should perform better than top and bottom, especially on tech forums.

In your face advertising on forums... sounds like short term thinking.

How about building a community of recurring visitors of loyal contributors that are welcoming to new members and go out of their way to help them ?
That's the long term view and IMHO it's NOT compatible with in your face ads.

How about building a community of recurring visitors...

Good point. I used to obtain double digit % CTR with in your face advertising. But I changed my model to grow bigger, making up the difference with MORE visitors and loyal contributors.

Please be careful about in your face advertising. There is an algorithm that can penalize your forum for that. Do not be caught up in the "Page Layout Algorithm [googlewebmastercentral.blogspot.com]."

It's probably a better strategy to NOT utilize overly aggressive advertising on your forum.

^^^ Spot on.

I built a forum which I later sold for a tidy sum - it was and still is one of the largest forums. The growth curve was great but slowed significantly with the new owners due to their strategy of squeezing it for all they can.