a. Strictly follow the rules mentioned in Adsense policies. You will always earn more revenue from Adsense by playing it clean.
b. Never modify the Google Adsense HTML code.
c. Don't ask your friends or visitors to click on your Google ads. Do not include incentives of any kind for users to <- snipped -> Don't label the Google ads with text other than "sponsored links" or "advertisements.".
d. Don't click on your own ads - Google is much smarter than you think. You should not reload your pages excessively. If you are testing your website layout with Google adsense, follow some precautions. Or you can use the unofficial Google Adsense Sandbox Tool that is accessible from Firefox, IE and other browsers to see what kind of Google ads will be served based on content (website address URL) or keywords.
e. Don't place ads in pop-up windows, error pages or even empty pages.
f. Don't start a "adsense asbestos" or "home equity loan rates" website merely to make money from accidental clicks (accidence). You will never make money out these "made-for-adsense-only" websites. Instead, write on topics what you are passionate about. Don't waste your money on high-paying adsense keywords lists.
g. For short articles, CTR is best when ads are placed just above the content
h. For long articles, CTR improves if ads are placed somewhere in middle of the content - visitors read the long content and then they are looking for more resources.
i. Use Text Ads instead of Image Ads as users get more options. If you still want to display image ads, consider ad formats that support image ads - Choose either the 300x250 medium rectangle or the 160x600 wide skyscraper - or both, if you display multiple ad units on a page.
j. Google Ads without background color and borders always perform better. Make the border color and background color same as your page background color.
k. Always put ads above the main fold. Make sure that the ad unit with the highest clickthrough rate is the first instance of the ad code that appears in the HTML. Since the first ad unit is always filled before the rest, you want to make sure that ad unit is located in the best placement on your page.
l. Try setting the ad link URL color to a lighter shade. If your text is black, you may make the adlink as light gray.
m. Go Wide - The large rectangle is the best paying adsense format (336x280) - The Google Adsense Publisher team also feels that the best formats are the wider ones - the ad formats that contain the widest individual ads. Try using the 336x280 large rectangle, 300x250 medium rectangle, or 160x600 wide skyscraper.
n. Placing images next to ads or above ads does help in attracting user attention.
o. Blend AdLinks with other navigation links or place horizontal adlinks at the top of your webpage. AdSense publishers are permitted to click on link unit topics on their web pages, provided that they do not click on any Google ads on the resulting page.
p. Organize an Adsense Party for your friends and colleagues - Request them to navigate your website, watch their activity - it will provide vital clues about which regions on your website draw more user attention. Try putting ads near those areas. (Thanks Darren)
q. You can put upto 3 adsense units on a page. Try putting a large skyscraper on the right navigation sidebar of your website. That area is close to the browser scrollbar. You can also add 2 AdSense for search boxes, 1 adlink unit and 1 referral button per product (i.e., 1 AdSense referral button and 1 Firefox plus Google Toolbar referral button).
r. The first few lines of your content are an important factor for determining what Ads are served on your webpage. That's the right place to put keywords in bold (strong or <b> tags) or header tags (h1, h2, etc).
s. Always select the setting to open Google Adsense search box results in a new browser window, so you won't lose your visitors. Click the Open search results in a new browser window checkbox and this add target="google_window" to your form tag.(Yes it is allowed by TOS )
t. Maximum people think the search box is on the top right corner. So you know where to put it.
u. Don't syndicate full content. If people can read everything from the newsreader window itself, why would they visit your website where your ads are.
v. Use URL channels to determine performance of individual pages. I track my most popular pages with Google Analytics, Statcounter and create a channel for each of the URL. You can even track Adsense Clicks with Analytics
w. For low CTR pages, try changing titles or adding more content to get better focused ads
x. Block low paying advertisers with Filters. Why to loose a visitor for 0.01 cents. Use Overture or Google Adwords Keywords tool to discover keywords that are less popular with advertisers.
y. The AdSense for search Top Queries report shows you what your users are looking for, by listing the 25 most common searches conducted through your AdSense for search boxes. Use this report to identify additional topics to add to your site, or to keep track of your most sought-after information. Focus and improve that content.
z. Not everyone has a RSS reader. Use RSS to Email services like FeedBlitz, Bloglet or Rmail to let users subscribe to your blog by email.
