Sure, it can be. I have looked into many solutions and either they don't do enough (if they are free opensourced ones) or they are CRAZY ridiculous expensive!
As in $2500/month expensive!
Then there are some integrated into shopping cart vendors like 1shop (whom many of my clients use) that are easy to setup and work just fine, but they do have a HUGE drawback in my opinion.
Most need you to link to the program on their website!
Sure, it's easy to copy and paste the code, but it TOTALLY misses out on the biggest advantage I see in running an affiliate program, INBOUND LINKS!
That's right, according to me the very best thing about an affiliate program is inbound linking. Think about it, why send out hundreds of emails asking for links, or worse yet link exchanging when you can aggressively promote an affiliate program that has real benefits for your partners sites to use because it can make them money!
Let me introduce you to Post Affiliate Pro! For $100 it is hands down the very best of the best affiliate programs that exists.
It is powerful, flexible enough to integrate into any shopping cart, customizable, they'll even code features into it it for you. We had a program built off of it for a few hundred bucks, it was delivered fast and bug free!
And get this...
They offer a stripped down freeware version you can try before you buy the real program, which lays right on top of the OpenSourced one, so setting it up need only be done once!