Here is the system:
Step 1 - find a product to promote from Clickbank
First of all, find a product to promote. Just go to Clickbank and register as an affiliate.
Then, find a product which solves a desperate problem. For example: lose weight, speed up PC, dating, some self-help products. You get the idea - find what people really want and are willing to spend money for.
In my experience you will make less money if you promote such products as "learn Spanish". But if you will put this method on steroids, you will need to enter lots of different niches.
You may also promote physical products. Just go to Amazon and register as an affiliate there. However, you will get only 7-15% commission, but people will trust you more, so you will make more sales.
Step 2 - mask your affiliate link
Just go to bit.ly and shorten your affiliate link (affiliate links look really ugly). You may customize that link as well (you have to register) by adding something related to your niche. For example:
You may also use your own domain name to set up redirects. That will look even better, because many people don't even know what bit.ly is.
Step 3 - go and find what people want!
This is the most important part. You need to get a Twitter account if you don't have one. Then, go to search box and enter... a problem. For example: "I must lose weight -www -http".
I add "-www -http" to filter the results - Twitter won't show tweets with links (usually these links are to products and people who post links don't have problems)
Then just simply go through search results and reply to tweets by clicking "reply"!
Two different strategies
You may post your affiliate link in the first tweet, or you may post that you know how they feel or something like that (lots of people will reply back), so you build trust and relationships and you are not identified as a spammer.
However, I should mention that every tweet should be unique. But you don't need to change a whole sentence, just change one word and that's it. You want to do that, because if you don't - Twitter will suspend you account.
You also don't want to post more than 20-25 tweets from one account per day. If you post more - you will be identified as a spammer and Twitter will suspend your account. Just simply register tons of accounts.
Step 4 - help them!
The key with this method is to help. If you don't help people they are not going to trust you, so you won't make any money.