I bet that title got your attention, right? Well I hate to tell you this but the truth is there are no AdSense secrets. It's all nothing more than hype put about by various internet marketers who want you to buy their product.
Okay maybe that's a little harsh as there are some very good AdSense guides out there, but the point I want to get across is that the real secret is that anyone can make money with Google AdSense. All you need to do is create a website or blog with quality content, display the AdSense ads in the most prominent places of every web page (ie where they will get the most clicks) and drive traffic to your site. Sounds easy I know, but that's all there is to it.
The crucial part is getting traffic to your site. You can create a site with great content, with ad blocks in all the right places, but if no-one knows about its presence then you're never going to get anyone visiting your site and clicking on your ads.
There are numerous ways of getting traffic to your site. These include things like exchanging links with other related sites, obtaining links from directories, posting on forums, creating blogs and linking to your site, writing articles and submitting them to article directories and ezine publishers, creating viral ebooks, and so on.
Once you have traffic to your site you can then start testing your AdSense clicks and ad placement to increase your earnings further.
There's no hard and fast rules that apply to every single site because every site has different layouts and will have different 'hotspots', so testing is vitally important if you want to increase your click-thru rate.
There are, however, a few things that you should consider to maximize your AdSense earnings. Firstly, I would say that it's always a good idea to make sure your ads blend in with your site as much as possible so they don't look like separate ads.
Remove any borders and background colors and use the same color link text as the other links on your page. Also, it's always a good idea to place a large ad block above the fold so it's viewed by your visitors as soon as they enter your website.
In addition, I've always found that ads that are displayed within the actual content (about half way down the page) also do well, if the page contains a lot of content, or at the end of your content for shorter pages, so you give your visitors an opportunity to click on your ads when they've reached the bottom of the page.
I don't personally like skyscraper ads, but as I've said before it's all about testing. You may well find that for your own particular site layout, these ad blocks perform well and achieve high click-thru rates.
Other things you can do include tweaking the keyword density on each page to ensure that the right types of ads are displaying, as well as removing the 'advertise on this site' text (which Google allows at the time of writing).
Ultimately though it's all about creating quality content on a regular basis, driving as much traffic as you possibly can to your sites using the various different methods of generating traffic, and testing different ad placements to obtain the maximum number of click-thru.
They're the real AdSense secrets.