Tip: See my list of the 
MostMost bloggers have heard about Google AdSense. AdSense is an advertising network developed by Google. The principle is that Google analyses the content of your website and interests of your visitors and tries to provide ads relevant to them. I have experimented a lot with it in the past, but as you may have noticed, there are no longer any AdSense ads on this website.
How people make a living out of AdSense
Most people think that no matter what your website is about, if you just put AdSense banners on it, you will experience a steady flow of income from that moment on. You probably will, but if it is an educational blog, it may be as little as a few cents per month. To understand why, you have to understand what people who make a living out of AdSense do:
1) They research what keywords tend to have the greatest CPC (the amount of money they get per click). For example, insurance companies sometimes pay as much as $50 for a click.
2) They set up a website specifically optimized for such keywords. This website often contains very little useful information (it is just a very generic description of the topic) and is written in such a way that a visitor actually wants to find more information on the topic elsewhere after finishing reading the website.
3) They use whatever technique they can to make their website score higher in search engines, and they spend a lot of time doing that.
4) They add a lot of aggressively positioned AdSense units to the website—units that unnaturally break the flow of text and make sure you notice them even if you don’t want to.
Now, you see how this overwhelming system works. Say you are interested in getting car insurance. You type some related search query into Google and click on some of the first few results. You start reading, but you feel that you are not really getting much useful information. Then your eye catches a link that looks like it could provide some further insight. Before you even realize that it is an ad, you click on the link, and the owner of the page gets, say, $2 (because it was in a very high-paying field).
How not to make a living out of AdSense
What do educational bloggers actually do? They do the complete opposite:
1) They research topics they are interested in and select those that they find intriguing or intellectually challenging (in other words, something that is worth writing about) which is usually in a niche where advertisers don’t pay much.
2) They write articles about these topics on their own blog which is not optimized for a single specific topic, and this causes visitors to see ads unrelated to the article they are reading.
3) They build communities of similarly thinking bloggers and regular readers. They don’t invest time in creating fake websites or other techniques to unnaturally improve the ranking of their articles.
4) They add unobtrusive ads, perhaps under the heading, at the end of an article, or to the sidebar, so that regular visitors don’t find them annoying.
What happens when someone visits the blog? They find a decent page containing a wealth of information on the topic they were looking for. They find most of the information they needed in the article they are reading, so they will most likely not click on any of the ads to find more information on the topic. Even if there is an ad that they would genuinely find interesting, it will probably go unnoticed because it is unobtrusively placed.
How much can you earn?
It happens from time to time that a visitor was actually looking for something else and he hadn’t found the information he was looking for (or he is genuinely interested in the topic of an ad). Then they may actually click on an ad, and you get… 5 cents? 15 cents? Perhaps 30 cents, if you are lucky. Of course, it depends on the topic, but educational topics tend not to pay well. (Well, some do, but the high paying ads are so obviously commercial and low-quality that it is hard to imagine anyone would ever click on them.)
Imagine your website gets 100 visitors a day, which is not at all bad for an educational blog. If the ads are not aggresively positioned, your CTR (click-through rate) will probably be as low as 0.1%–0.5%. Say you are lucky and you get a CTR of 1%. Say your niche is still above average in terms of what you get per click, and you get 20 cents for each click (you will most likely get less on average). So, every day, one person clicks on an ad, and you earn 20 cents. So, after a month, you have made… 6 dollars. Yaay. That’s about three coffees at Starbucks.
At this rate, you would have to have about 30,000 visitors a day coming from search engines (regular visitors become ad-blind very quickly) to make a decent living out of writing an educational blog, and that only if you are extremely lucky. In most niches, it would have to be more like 300,000 visitors. For most bloggers, these numbers are highly unrealistic, and there is a much better way to get at least some reward for your work.
