If you are an affiliate marketer, then you are in business. Therefore, you should treat it like a business. Keep in mind that Linkshare, Clickbank, Commission Junction and all the other affiliate marketplaces are going to report your earnings to the IRS.

Each of them requires that you provide a Social Security Number or EIN number when you apply with them. These numbers are used to report your earnings. At the end of the year, you'll receive a 1099 form which is the IRS earnings document given to Independent Contractors.

Since you have to pay taxes on your income, you should take care to make sure that your income is properly calculate. Remember, gross adjusted income is going to be the total amount that you earned - your expenses. For this reason, you really need to keep track of all of your affiliate marketing expenses.

Keep receipts and track all the following:

* Web Hosting Costs

* Affiliate marketing tools (such as your WordTracker membership fees, the cost of products like Adwords Analyzer, etc.)

* Any PPC advertising that you purchase.

Don't do as I have been prone to do and wait til the end of the year before you start putting these numbers together. You'll forget many and you won't be able to gain access to others.

For example, with PPC advertising, Google seems to keep records online forever. Great. But Overture only keeps the last 90 days and you can't - I repeat - You CAN'T get those records older than 90 days. (Ask me how I know :(

Getting receipts means that you'll have to think ahead. When you buy something online, print the receipt page. When you subscribe to a service that may pull a fee from your checking account or credit card account on a monthly basis, make sure to opt in to any e-mail notification of transactions that you might be able to get.

Print everything out and put it in a folder for that years tax records. You won't regret it when tax season comes along.

You will also get a much better picture of how much money you're earning. I think a lot of affiliate marketers brag about their checks, but conveniently forget that out of the $10,000.00 they earned last month, they spent $8,000.00 for PPC advertising, $27.00 for Wordtracker, $100.00 for their web host, ect, etc, reducing their actual profit to enough to buy some bubble gum.

There's great software that makes all of this easier of course. Quicken or MS Money Home and Business editions or PeachTree accounting would all make the whole process of tracking these numbers much less painful.

Finally, there are real benefits (and some costs) to incorporating yourself. Incorporating changes the tax rules and create scenarios that let you put more of your profit into your pocket. They also help to shield you from liability. I'm not a lawyer, so I'd recommend talking to an tax law lawyer. I incorporated in Florida and the entire expense was about $495.00.