I think it also depends on the niche of your blog/website, the method you are trying to earn $ - by impressions or by business referred, the products you try to market etc…

I have asked similar questions on this topic:
good affiliates/widget program for investment/financial/business blog

good affiliates/widget programs for innovation/science/entrepreneurship/IP blog

1. One gives me suggestion of Commission Junction.
http://www.cj.com/

2. The other gives me suggestions of ClickBank.
https://www.clickbank.com

3. Mahalo widgets are lucrative too: M$1 for 1000 views.
http://www.mahalo.com/mahalo-widgets
Good as impression-type affiliates/widgets program.

4. My blogs also have RentACoder, GetAFreelancer, Amazon affiliates program.
There are clicks but so far no businesses.

For Twitter ads, try to search in one.forty (a Twitter apps platform website):
http://oneforty.com/category/Advertising

Some of them may be are Twitter ads, for examples:
Adjix
Magpie
ad.ly
sponsoredtweets
http://sponsoredtweets.com/

I didn’t use Twitter ads as follower may disappear fast.
You may lose the credibility and trust.

I do not have my website up yet, but I have been researching using affiliates to add income when it is up. I agree with @wy in that it really might depend on what your niche is, as in what is the topic of your blog. You want affiliate programs that really mesh with that, so it seems natural that once people read your stuff, they will want to check out the affiliates that you have listed.

You won't get very far merely having links to affiliates though, as I understand it, if you are not writing the content behind them. I'm not talking about - here's a great website - go buy stuff from it but rather discussing the content related to the affiliates.

For instance, my blog will be about education. I will have posts about teaching and learning, curriculum guides, etc. Some natural affiliates would be educational book publishers or online learning sites. Now that I know what affiliates are (I admit to always being a day late and a dollar short when it comes to these things), I see them everywhere. I have my eye on a few already because I my normal surfing for education related stuff and came across some affiliates that I think will be perfect.

Of course, you always want to read what their terms are, how long do they allow for people to come back and buy after visiting your website (2 weeks, 30 days, 60 days, etc)? How much commission are they giving you? How often do they pay? etc.

Your best bet is to choose affiliates of products or services that you would personally use. You can talk candidly about the topics and guide people to your preferred businesses this way. Some of the businesses you are interested in being affiliated with may also be in an affiliate network.

An alternative is to sign up with an affiliate network or company that markets affiliates (the first two that that @wy listed are good from what I have read). You can then browse their holdings and see if anything of interest pops out at you. Then you build your website around that. However, if the topic isn't something that will sustain you for a long term, then it might not be a good fit (i.e. you don't update the information about the topic regularly).

So I would say, use the niche that you are developing in your blog and find companies that sell those products/services. If you look around on a website, you can find out if they have an affiliate program.

Hello ditesco,

I promote an ebook called The Gallstone Elimination Report. It pays you 75% of each sale (which comes out to $32.51). This is one of the highest commissions I've ever seen.

They have a great-converting sales page that you send your visitors to. It does all the selling for you. In fact, I've sent 89 visitors so far and have already made 2 sales (2 sales x $32.51=$65.02).

Check it out:

http://www.gallstoneadvice.com/affiliates.html

They have a lot of excellent free marketing tools to get you started on the right track.