There are many ways to make money online but I’ll narrow them from experience how others and myself make money online.
1. Article Writing
There are companies out there that pays you for your articles. This ranges from $3-7 per article depending on quality. There are also lots of Internet forums which requires articles and they are willing to pay on average $3 per article. If you are able to write good articles withtout grammar mistakes, you can earn easily $50 a day writing articles. As you progress in your writing and know how to write as the market demands, you can demand up to $100 000 per copywriting. It is quite common knowledge that this is the asking price for top Internet article writers today.
2. Affiliate Programs
There are lots of vendors who are willing to share 50%-75% of their sales value when you make a sale for them. Popular sites such as Clickbank and Commission Junction are a good place to start if you are interested in affiliate programs. However, this is not an easy path to follow as you need to be competing with lofs of otherInternet Marketers. Also if you are planning to write an ebook or a software, these places are the more established place to market your products. Imagine having more than 100000 people promoting your products online and they work on % basis only.
3. Ebay
You can sell almost anything on Ebay. All you need is to invest in a shipping company like FedEx or DHL, have a good range of products and price must be cheap. This is suitable if you are a distributor or manufacturer who wants to bypass the middle man and offering great discounts to customers. There are also many collectors in the world and most of them go to Ebay to search fo this. I personally know someone who is trading stamps online at Ebay for many years now and each stamp he sells about $0.5-5000 each. His collection he told me he has over 30000 stamps.
4. Service Provider
If you are good at what you do, and you want to expand your market, you can certainly market it online. Whether you are a web designer, or web programmer or simply talented to do something, you can sell your services online. There are hundreds of websites that you can promote your services, all you need to do is search online for them.
5. Sharing Revenue
There are lots of advertising companies that pay to publish their advertisements and in return will reward you if there are clicks on their advertisements or purchase made. Google adsense is one of them. The websites are made are optimize for these ads and one can earn a good income from just sharing avenue with these advertisers. On average 1% of visitors will click on your ads. So for example if each click earns $0.30 and your website can generate 5 clicks a day, that is $1.50 per day on autopilot. Top earners manages probably 100 sites a year and with just a low estimate of $45 a month per website, they can generate $4500 a month with almost no maintaince and cost. I do have seminars on these on a weekly basis if you are interested to know more.

6. CPA
I believe this is the main in thing today. CPA is an acronym for Cost per Action and refers to “ads” that are sold on the basis that money is only given when a certain action occurs because of the ad. A CPA ad could be one in which a publisher gets paid for people that click thru an ad and sign up for a newsletter or enter a contest or fill out a form for more information on a product. Many consider direct sales or Cost Per Sale ads, and CPC ads to also be a form of CPA. But CPA usually refers to being paid for leads, sign ups, and so on.For example if you can get people to put in your email, you get paid $1.00. So if you can drive targetted traffic to a site and all they need to do is leave their email which is FREE, you get paid $1.00! This is very easy to do if you know how. Some other CPA actions are like leaving your postcode, answering survey questions, purchasing a trial offer which is one of my favourite. Some trial can be purchased for like $0.1 cent and I get paid $50 for that! Totally mind blowing. Reason being is these companies actually pay you on value of business per year they can obtain from a customer instead of a percentage of sales you make.
7. PPV, PPC, PPP,
Pay per view, pay per click, pay per download is what those acronyms stands for. You can drive traffic to your website and advertisers pay you a small fee for every 1000 views. Usually the range is $0.05 for 1000 views.
Pay per click is similar to revenue sharing and you can expect to get paid like $0.01 to $0.05 when someone clicks on the ads.
Pay per download is when you entice the visitors to download something for free and you get paid like $1.00 for each download. It can be latest trial games, or latest videos or software in the market.
8. Membership Site
If you are choosing this path, you can set up your skills online and add value and people will subscribe to you. You will get residual income on a monthly basis and combined with your affiliate skills, this is a good way to make lots of $$.
I am sure there many other ways to make money online but I summarize to the most popular ones today.