There are definately more than 10 ways to earn an income from the Internet but i’ll try get the first 10 that comes up to my mind here.

So here’s the list goes:
1. Google Adsense
You own a website or blog, you post up the Java script provided by Google, you earn penny to dollar when someone clicks on your ads. you’ll need traffics, lots of them. traffics from search engines, article portal, pay-per-click ads, forums, viral emails, and so on. the good news is that you don’t need to have targeted traffics, in fact random search sometimes will earn you more as they navigate away from your site via Google Adsense.
2. Pay Per Post
Pay Per Post is a new sort of online income source. i take it as the new online creatures born following the born of weblogs. to get paid from this, you write stuffs that the advertisers want you to write on your blog. in general, you will need a blog with some what popular and certain level of Google PR. Earning your money via Pay Per Post is pretty similiar like the book author, the only different is the author get passive income via book’s copyrights but you don’t. 
3. Affiliate business
You try to sell something for the merchant online. by subscribing as the affiliate to a merchant (via aff network or in house program), you get a link with a tracking code hide in it and post it on your website, you make money everytime someone follows that link and spend money at the merchant site. the hard part in affiliate business is that you need highly trageted traffics as you earn, ONLY when someone spend.
4. Link brokerage
Make a website, boost up its google PR, and sell link ads space to other webmaster. its like in the real estate business, you rent your shop spaces for advertisers to post their ads. with google getting more and more smarter in detecting paid links, i expect link brokerage business will turns slow and eventually die off. but who knows it will stay in business for how long? i would like to hear more insights from the pros.
5. Online auction
In Malaysia, you do it at lelong.com.my; in United States, you do it on ebay. more or less the same concept, more or less the same money. any buy-sell business should take the advantage provided by these auction website and push their biz online. its the most convenient and simple online biz modal for a tech-dummies anyway.
6. Online store at Yahoo
Pretty similar with opening a store at online auction website. the main difference is that you pay for a higher rental price, you work out more for your biz webpages, and you dont have the choice to sell your item in auction system. alternatives for tech-dummies to push their business online in the easiest way.
7. Write an ebook
Declare yourself as guru in certain industry, write an ebook in pdf format, sell it, via click bank or ebay. some ebook writers do WRITE and provide valuable guidance; others, they just RE-WRITE what the others had written. in case you are not that expert in the field, do the Internet world a favor, do not consider this option as your online income source. the Net is already full with crappy ebooks and they dont need yours!
8. Auto surf sort of scams
Yes, 99.9% auto surf programs are scams. want to be a scammers? go join any of those programs. you pay a little amount of money to join into the program, you login every now and then to let the program auto surf for you, and you gain pennies everyday for ‘working’ on this. you think you are smart, earning easy bucks online, but indeed you are just the little scammers being scammed by the bigger scammers (the program owner), cheating advertiser’s ads budget.
9. Online traders
Whether is options, Forex, futures, commodities, or stocks; you can trade’em online. most day traders work at home, via Internet. so yes, its a method to earn money online - if you manage to beat the market and stay positive in your trades day in and day out. its a high risks job - if you trade on margins (in Forex, you can leverage 200 to 1 on your capital), you might win millions out of nothing; or vise versa, lose it.
10. Filling up survey forms
You can get paid via filling up survery forms. but the chances you get more than 5 times of survey is same as the chances you hit the jackpot once in your lifetime - the chances on doing this for living is slim. but anyway, it can sum up with the other nine methods above and make a good amount of income.
These are the 10 ways you can use to make money online. can you think of more? welcome to beat me up with better ideas.