Adsense
The 5 Most Important Things You Must Know About AdSense 
By Joel Comm 
Whether you're just starting out with AdSense or whether you've been using it for years, the success of your ads will depend on knowing five absolutely essential pieces of information about AdSense:
1. AdSense Can Make You A Huge Heap Of Cash 
Lots of people make the mistake of believing that AdSense is only good for bringing a site a few extra pennies a month. Wrong! AdSense can fund your lifestyle - if you get it right. 
2. Junk Sites Get Junk Income 
But just because it's possible for a site to make a lot of money with AdSense, it doesn't mean that any site can make a lot of money with AdSense. Your site must have good content that can attract users on its own merit. There are a lot of different strategies available for producing good content for your site. You'll need to use them if you want to create the sort of site that makes real money.
3. Your Choice Of Ads Matter 
One of the first things that you'll have to do when you join AdSense is to pick the types of ads you want to display. Success relies on following certain principles that encourage users to click and persuades them that they've got a reason to do so. You'll need to know those principles.
4. You Can Influence The Ads You Receive! 
Here's a little known AdSense secret: you do have some control over the ads that get served on your site. That control isn't unlimited - but it is worth exercising. It's also a little complicated but it's got a lot do with keyword hotspots located in each Web page. (I explain it all in my book, Google AdSense Secrets.) That's definitely something you need to know!
5. Your Stats Are Your Best Friend 
The stats you get with your AdSense account might look complicated and well, a bit dull... but they're packed with useful information that can have a massive effect on your revenues. To make real money with AdSense, you need to know what your stats are telling, what they're not telling you and where you can find out more.
There's a lot you need to know to make serious money with AdSense. If you're missing that information, you're just throwing money away
AdSense allows website publishers to display contextually relevant advertisements on their website. If a web visitor "clicks" on an advertisement, the web publisher will earn a percentage of the advertising revenue generated as a result of the click. Many webmasters have built content websites around the Google AdSense model. In many cases the specific intent of the webmaster is to profit from Google AdSense. Other webmasters use Google AdSense to supplement their revenue. Regardless of the webmaster's intent, the following tips will help webmasters looking to profit from AdSense.
Top AdSense Tips:
1. Niche Sites.
Targeted niche sites that have a clear theme, tend to generate more advertising revenue simply because it is easier for these sites to achieve decent search engine placement. Be warned though, you want to choose a niche where there is a sufficient number of advertisements available.
2. Target Keywords.
When determining the site's focus, consider how much advertisers pay for the advertisements. If the site is focused on ringtones, like Ringtone Central http://www.ringtones-central.com the payout per-click is going to be very small because ringtones are not high ticket items and advertisers will not spend a lot on pay-per-click advertisements. With less obvious markets use Overture to determine how much advertisers pay-per-keyword. It is usually similar on Google. Search Overture for a keyword then click "View Advertisers' Max Bids" in the top right corner. This will show the Overture inventory and how much is paid per keyword. Because the market has become very competitive, it is difficult to rank well in search engines with a new website that is optimized for the terms that have the highest payout. Consider targeting terms that are moderately priced.
3. Aged Sites / Time.
Over time as a website is spidered by Google, advertisements will generally increase in relevance. In general, older websites will rank better in search engines. The closer the advertisements relate to the webpage's content; the higher the "click-through" the publishers will see 
4. Coding.
In order to minimize a website's maintenance place the Google generated AdSense code in the website template or an include file. This will allow you to easily experiment with different advertisement sizes and ad placement, and keep web maintenance to a minimum.
5. Tracking Channels.
In order to know how effective a specific website or ad placement is, use distinct channels and subchannels within Google. This will allow you to discern what performs best on a specific website. Using channels will tell you what sites are making money, what advertisements are making money and what ad position is the most profitable on a specific website. Keep in mind that you should run an advertisement for a full week, in order to properly test its effectiveness. Different days of the week will have varying web traffic, so comparing one week to another will give the most accurate reflection of how effective a campaign performs. The same is true when testing different advertisement sizes, placement or color schemes. Be sure to leave campaigns in place for one week. Again, different days will often result in web traffic fluctuations. Comparing web traffic, week to week will give a clear indication of what ad formats perform the best.
6. Integrated Ad Placement.
Many webmasters have been successful at integrating advertisements into a website. The easiest way to integrate an advertisement into a website is to remove the advertisement border. This will allow the ads to better blend with the webpage. Google recommends contrasting the link colors with the website colors to increase click-throughs. It is also suggested that webmasters randomize the color of the advertisements, so that frequent users will not naturally "filter" the ads. Examples of integrated ad placement: http://www.golf-clubhouse.net or http://www.security-protection.net
7. Number vs Value of Advertisements.
Place up to three advertisements on each page. Additional advertisements drop in value and dilute ad inventory so publishers should be cautious in adding more advertisement units. In other words you want to serve the most expensive ads at all times.
8. Hot Spots.
Like web copy, above the fold holds true with AdSense as well. This means that advertisements that appear without having to scroll will be read more frequently. Hot Spots are areas on a web page that result in a higher percentage of click-throughs. According to Google the highest paying advertisements are located on the hot spots. Hot Spots Map: http://www.small-business-software.net/heat-map.htm Google does not indicate if image advertisements or text ads perform better, so webmasters are encouraged to experiment with both.
9. Highest Performing Ad Sizes.
According to Google the 336 x 280 rectangle, the 300 x250 rectangle and the 160 x 600 sky scraper result in the highest number of click-throughs. Depending on the website's design and layout, publishers may experience different results with different ad sizes, placements and color schemes. Experiment and track the results for each website to maximize the AdSense payout.
Removing borders from your AdSense ads can lead to a significant boost in CTR. Use Matching Fonts Match the font of your site content to the fonts of your AdSense ads Use Matching Colors Match the colors of your AdSense ads to the colors of your site content. Make the ads look like content and more visitors will look at them. One exception to the color matching rule is sites that are designed to appeal to scammers and spammers. Those sites sometimes perform better with highly contrasting colors. Use Blue Links Another exception to the color matching rule is to set the links in your AdSense ads to blue. Blue links tend to have a higher CTR than other link colors, because people have become used to clicking blue links. Use Large Ads Larger ads outperform smaller ads.
Wider ads also outperform more narrow ads. The Large Rectangle (336x280) is the best performing ad unit. Use Lots of Ads Google allows you to use three ad units and one link unit on each page. Use them all. The more ads you have, the higher your Page CTR will be. Place Ads Above the Fold "The fold" is industry jargon for "the part of the page that the user sees without scrolling down". This will vary depending upon the resolution of the users screen and the size of their browser window. Place as many ads as possible above the fold. Ads placed below the fold are seldom seen and seldom clicked. Place Ads on the Left Web users are accustomed to seeing menus on the left side of the web page. Move your menu to the right and place your AdSense ads on the left.
Use the Heat Map Use the Google AdSense Heat Map to determine where to place ads. The darker spots are areas where users spend more time looking. Place your ads in the darker areas. Integrate Ads with Content Visitors will be reading your content. Keeps your ads as close to your content as possible to ensure that the visitors also look at your ads. Use Custom Channels Use AdSense's Custom Channels to test the performance of different ad sizes, placements, colors and fonts. Don't use Low-Paying Competing Ads Don't clutter your page with competing ads that don't pay. If a user clicks on an ad that pays you $.01, they are not clicking on an ad that pays you $.30.
Use URL Channels Use AdSense URL Channels to determine which pages are making you the highest CTR, CPM, and earnings. Focus your efforts on building pages like those. Use an AdSense Reporting Package Google only supports 200 channels. If you have more than 200 pages, use AdSense reporting software to give you more insight into your AdSense earnings. Don't Compete for Other Peoples High Paying Keywords If a keyword is on a list of high-paying keywords, that means that thousands of spammers are already competing for that keyword.
Don't be a follower. There is no money in being one of the crowd. Do Compete for Your Own High Paying Keywords Monitor your AdSense URL channels to determine which keywords are making you the most money. Compete for those keywords. Build more pages optimized for similar keywords. Get inbound links for those keywords. Spend your time and efforrt on the keywords which are making you money. Increase Traffic In the long run, the best way to increase your AdSense revenue is to increase traffic to your web site.