What do you need to make money with AdSense?

So, AdSense is free, easy to use, you get 68% of the revenue – what else do you need to make money with AdSense?
You need a content rich website
AdSense loves content rich websites. Content can be of any kind (including text, images, videos), provided that it does not violate the AdSense content policies.
It is suggested though to have text on the pages as well so that the AdSense crawler can understand better what the website is about. AdSense is more suitable for websites that publish articles, case studies, how-to guides (like this one), but there are also success stories of other types of websites as well.
You need a high quality website
It’s not enough to publish content that does not violate AdSense content policies but you also need to provide for high quality content on a high quality web site. Google is liable to advertisers for the money the pay so they don’t want their ads to appear on low quality websites. In the past this was possible but the last couple of years they have more strict policies on the type of websites you can run AdSense.
You need a LOT of traffic
AdSense is a good way to make money online and it is perhaps the easiest method provided that you have a good amount of quality traffic coming to your website. I cannot give you an exact number because the amount of money you can make depends on the earnings per click (EPC) and click through rate (CTR), but I don’t usually advice my clients to run AdSense on websites that have less than 300-400 unique visits per day.
In general though, the more targeted traffic you have, the more money you can make with AdSense.
You need to target the right keywords
If you target the right keywords in your content then you can make more money with AdSense or with any other advertising platform. What are the right keywords? Keywords that are: (1) used by advertisers to promote their products so the competition is greater and (2) action keywords. Action keywords are more effective since the users are more likely to ‘take action’ i.e. convert after they click.
Let’s look at the following example: Assume that you have 2 websites in the weight loss niche that are running AdSense. Both websites receive the same amount of organic traffic and they have the ads in the same positions. The first one is getting visitors searching for: ‘weight loss tips’, ‘how to lose weight’, ‘lose belly fat’ and the other one is getting traffic from keywords like: ‘why drinking water is important’, ‘what to eat after dinner’, ‘how many meals to eat per day’.
The first website is likely to make more money with AdSense because more advertisers are interested for those keywords so the number of available relevant ads will be greater. Users are also likely to click the ads more often since users looking for tips or solutions to their problem are more likely to click on a relevant ad than users who are searching for general information.
This is also the reason why organic traffic is considered to be more valuable than any other form of traffic i.e. because it is highly targeted and converts better.

You need to fully comply with AdSense policies
As I said above AdSense represents 1/3 of Google’s revenue so they take the whole program very seriously. While it is relatively easy for everyone to get an AdSense account, if you don’t play by their rules 100% you risk losing your account.
Even if you are an existing or new AdSense publisher make sure that you read their policies before implementing AdSense on your website. Remove from your mind any ideas for tricking the system and always remember that they have hired the best people to make sure that nobody will be able to bypass their rules and policies.