In the beginning, there was banner advertising.
You could earn $20 cpm just for slapping up ad code. Publishers were happy, VC funds were flowing, and advertisers were getting their traffic. And it was good.
Then as the VCs shared in the fruit of knowledge of truth and reality, the bubble burst, and publishers witnessed the fall of the banner ad, into sub-dollar CPMs. It hit across the board.
Behold, there was light!
Affiliate marketing then began its jump into the glory of the online marketers' attention.
During this time, you could slap a few affiliate banners up, call it a day, and watch rev bounce around where the straight cpm banner figures were. Six one way, half a dozen the other.
But some smart guys worked, and learned how to really promote affiliate programs. They figured out how to presell, entice visitors to click and buy, and even build sites around affiliate programs. This is where the money was. Done right, it would kill the early glory days of $20 cpm banners, by a multiple.
Affiliate marketing became all the rage of the day, and you could hear the cries of new marketers on forums everywhwere, whining about not being able to make money. "Everybody else is getting rich! Where's mine?"
Well, they slapped up some banners and called it a day. That method sucked then, and still does today.
The next BIG Thing
Enter the current wave of AdSense and contextual advertising. Back to the days of slapping up some code and earning double digit cpm, no problem. And many people are happy.
Meanwhile, the real affiliate marketers are still methodically and quietly cranking out new sites and promotions daily. If you listen, you can even hear their keystrokes late into the night.
So today, to take the easy road and slap up some code, call it a day, and watch the stats - AdSense is probably your best bet. If you're ready to make more, and don't mind spending the time to do it (yes it may require w*rk), affiliate programs can produce much more, in many cases.
Consider some of those AdSense ads running on your site, the ones that go to affiliate promotions. Think about it, your visitor is going through that link at $x.xx. You get your cut, AdSense gets theirs. The affiliate paying that is still making enough margin to pay for the click and clear revenue. How much more could you make, if you sent that traffic straight to affiliate programs yourself? You would make your EPC, Google's cut, plus the add'l margin that AdWords affiliate is working with.
For example, say you have a good site about finance. It gets decent traffic, has content about loans, stocks, debt, whatever. You plug in adsense and go on to the next project. Sure, it will make good money, and if cranking a site out, forgeting about it (advertising-wise) and then moving on is your thing, contextual is for you.
However, a smart affiliate will promote loan merchants, brokerage accounts, consolidation companies and whatever else fits the site. He'll seamlessly weave the promotions of these companies into his site. He'll get merchants that let him host his own forms, and take leads so the visitor never leaves his site. He'll negotiate even higher commissions.
He will own that visit and cash in more revenue, a LOT more than AdSense clicks. It might take some time, trying different merchants, different site copy, ad placement, different promotions, tweaking this and that, etc. etc. He will work for his add'l revenue, and it will pay off.
THEN he'll leave it on autopilot and monitor stats, just like those addicted to CrackSense.
There are still some sites and topics that will do better with contextual ads. Say your kid likes tinkertoys or erector sets and you build a site together. It turns out you did well with it, and it get links and ranks well. There might not be a lot of good affiliate deals out there, but you can bet there will be some adwords on it.
Maybe you already make money some other way, sell a product or whatever, and are just looking for some supplemental revenue. Contextual will probably be the way to go.
There are no hard and fast rules in this business. Affiliate vs. Contextual is no exception.