1. A webpage. The days of being able to send traffic to an affiliate hoplink are over especially with recent changes in google adwords. A marketer must have webpages of their own to profitably earn commissions. This can be blogs, websites, squidoo lense or anykind of review or pre sell page. I don't recommend using turnkey pages provided by merchants. The reason for this is that there are likely thousands of others using these same turnkey sites. Your site should be unique. I also prefer squidoo lenses and blogs over websites because they are very easy to set up and offer seo benefits.

2. Traffic. After you set up your webpage you will then need traffic to make commissions. Large volumes of traffic is ideal but the quality of those visitors is actually more important than the quantity. Ways you can get quality traffic that is highly targeted and interested in the product you are promoting include ppc advertising such as google adwords, publishing articles like I am doing here, online classifieds and free traffic from SEO.

3. A System. To make your business more successfull you need a good system in place. This will make selling easier and more efficient. A good system will help you create webpages and articles quickly allowing you to grow your income faster. Just having a good plan and being well organized will make your business much more likely to succeed.

4. Good ad copy. You want to motivate people to go to your affiliate sites and make purchases so having good writing and ad copy is very important. Using words like free or free information in your ad copy will help get vistiors interested in your product.

5. Subscribers. Traditionally marketers use email lists. My personal opinion about email marketing is that with the spam problem and buyer resistance to email ads the days of email are numbered. That is why I prefer using blogs and lenses which people can subscribe to an RSS feed which is a good spam free substitute for email.

One that get a solid foundation in all those things I just mentioned should be well on their way to having a profitable online marketing business.