This article is written for the purpose of helping newcomers at InfoBarrel. I will only focus on clear facts (what are the ways to make money on InfoBarrel) and will not start discussing how to improve your income, how important keywords are, etc...
First, you are probably new here, so welcome to InfoBarrel, I hope you will enjoy writing here.
There are 4 ways to earn money at InfoBarrel:
1) Through Google Adsense ads displayed on your articles
2) Through Chitika ads displayed on your articles
3) Through Amazon affiliate sales
4) Via your referral
For each of those, you need to get an ID (directly from the advertising program, not from InfoBarrel) and set it up under "My Account" and "Advertising Profile". The full procedure to set up your Advertising Profile is fully described here.
Let us see each of them in details.
1) Google Adsense
This is probably the most important at the beginning. Unfortunately, it is also the most difficult to get. Google only approves applications from writers that have proven they were serious about writing online (15-20 articles, at least one month, etc...). Please check the "Getting a Google Adsense account" article for more details about how to get an Adsense account.
How do Google Adsense work? Basically it displays ads on your article based on the content of your article and on the preferences of the person reading your article. For example, if a football fan reads your salsa article, Google may display both football and salsa ads.
Most of those ads will only give you money if your reader click on them. Some will give you small amount of money ($0.01 or $0.02 at the beginning), just for the right to be displayed on your articles.
Warning: DON'T EVER CLICK ON YOUR OWN ADS. Trying to cheat will only result in you being banned from Google and this is a lifetime irrevocable decision. Don't try it, I mean it. As part of the InfoBarrel community, you should not click on other ads displayed at InfoBarrel (you may be accused of trying to give money to InfoBarrel by doing this). Don't ask your friends to click on ads either. This is cheating too and the punishment will be the same as stated earlier: lifetime ban. How do Google knows you are cheating? Let's say 100 people click honnestly on ads displayed on my article and 10 end up buying a product. You ask 50 of your friends to click on your ads and get 50 real clicks. At the end, Google will see that only 5 ended up buying something when they clicked on your ads. Something is wrong there, they will have a look and ban you directly. There is no warning.
2) Chitika ads
This is also an advertisement profile but it does not work the same way as Google Adsense does. It uses the keywords used by your reader to find your article. For example, you wrote an article about the Apple company. One person looks on google for facts about apples (the fruit) but finds your article and reads it. Chitika will then display ads about apples (the fruit) as this is what your reader was looking for.
Chitika generally generates less money than Google Adsense but is easier to get. Simply apply on their website and you will be set.
3) The Amazon Affiliates Program
This is no more based on clicks (you can click on those if you want), but based on sales. Imagine you write about diets and promote a wonderful motivational book about this topic. Someone clicks on your link and buys the book. You then get a percentage of the sale. The exact percentage depends on the type of the product, on how many sales you do per month, etc...
Applying for an Amazon Affiliate ID should be quite easy too. InfoBarrel integrates an Amazon box in all of your articles automatically, and you just need to enter the general category you think suits best with your article when you create it. You cannot choose precisely every single object displayed in that box. It will be automatically chosen based on the category you entered. If you don't enter any category (no one fit with what you wrote, for example), then default items will be displayed.
You can also link inside you article to items on Amazon but these links will count towards your 2 maximum outbound links you are allowed to in an article (plus 2 in your signature). Also, the links should be subtile. For example, "I recommend the latest book of this author", and not "Please click here and go buy the book of this author" (call-to-action link, where you invite the reader to leave).
If you invite someone to join InfoBarrel, your ads will be displayed 2% of the time instead of theirs. Don't see it as unfair for your referrals. What happens is the following:
Most of the time (more than 60%), it is the writer's advertising ads that are shown on his/her articles. The rest of the time, it is InfoBarrel's ads that are shown. It allows the site to stay free while maintaining this site, checking articles, holding challenges, etc...). It is in this "rest of the time" area that your ads will be displayed on your referral's articles, ie your referral will have the same amount of page views no matter whether he is your referral or not.
This is a great way to make money as you don't need to do anything (well you simply need to set your advertising profile correctly).
There is one more advertising profile not mentioned here. It underlines some words and generates money on clicks. This program is reserved for InfoBarrel only, you cannot activate or deactivate it either.
Finally, if you are part of another affiliate program (say you get money if someone buys an article at site X), then you can include a link to an item you promote. InfoBarrel has nothing to do with this either (your link, your program), but there is a limit of 2 outbound links inside the article and 2 in the signature (check the guidelines for more info).
I hope this article was informative and helped you understand a bit more about how to make money here. If something is still unclear don't hesitate to ask in the comment section, on the forum or in a PM to me. Good luck in your writing adventure!