If you have a site that's earning a steady revenue stream with Adsense, you've likely notice that only a few of your pages are earning a majority of your income. That's not a new concept -- the idea of 20% of your pages earning 80% of your revenue is also known as the Pareto Principle, and has been used frequently in economics over the past half century.
A #1 Ranking is not the End
I have met several Adsense marketers that have driven themselves to earn the coveted first position in Google for their particular search term, claim that they have tackled that mountain with much fanfare, and then move on to the next search term. Rinse and repeat.
They are leaving money on the table.
Those profitable pages can now be used as trust currency to build future articles. You don't always have to spend hours crafting a new concept, sometimes what your audience is after is a more complete explanation of something you've already posted. These tips can easily be applied to your most successful Adsense pages to create follow-up articles that your audience will want to read, and will help you earn as much as you can.
Narrow Your Choices
This approach will not work for all of your articles. You'll need to narrow your focus to just those posts that have been consistently earning for you. Start by listing your top five articles, in order of income generated. From there, create a short list of related topics to each of those articles. It's important to keep the focus on the topic of the popular article you've already written, both for human interest and for the SEO benefit of linking similar concepts.
Link to the Follow Up Article from the Popular Article
We've been taught to link to an article to build up its link juice. What if that article is already number 1 though, and has been for many months? That article has link love to spare, so start spending it where it can do some good.
It's important to add a link to your new article from the popular article that's already ranking well. Ideally, this would be added early in the post. If it doesn't fit in the first paragraph, there's no need to force it. Simply add a one sentence paragraph after the first one that says something like "For more information on [your topic], be sure to read [follow up article title]".
Use a Different Sized Ad Block
A key improvement, if you're able to specifically control the size of your ad blocks (and if not, why not?), you should use a different size on the follow up article.
Adsense marketers have been beat over the head with the concept of integrating ads into their content. This is certainly true, but when your visitors passed on the beautifully blended 250 x 250 ad on the first article, there's little reason to throw it at them again in the follow up post.
Try mixing up your ad block sizes on the follow up article and you will see normally poorly performing ad blocks surprise you.
Bringing it Together
By no means do I recommend throwing together a junk article just for the traffic and income. However, if you create a great follow up article and treat it properly you will greatly increase your earning potential. Sometimes a topic is so popular you can write several follow up posts!
One final note: sometimes Google will take note of the connection you've created between the two posts and will link to you multiple times on the first results page. At that point you've increased your presence considerably in the SERPs, which should improve your organic traffic as well.
For more tips on increasing Adsense revenue, try reading Increase your Adsense Income by 86% in 15 Minutes.