Couple of Newbie Clickbank Questions

Hi all,

I'm just trying to branch out a bit into my affiliate marketing career and take a look at Clickbank. Presently, I have a few websites where I promote products for other merchants using Wordpress posts for each product. So what i'm doing is already a bit similar.

I was looking at a few Clickbank tutorials and many suggested to write an article on your topic and place your code into the resource box and throughout the text. I was disappointed to find out that a few article directories don't allow this and so i'm looking for other approaches. Are the succesful Clickbank advertisers purchasing their own domain names and promoting various products through the same domain? Or are most still writing targetted articles and submitting them to various directories? Also, are people writing articles submitting the same piece or making changes if submitting to more than 1 directory?

If I take a look at the Nutrition genre in the Clickbank Marketplace there are many different sub genres like nutrition for body builders, cholesteral dieting, constipation, etc. Would I just create a nutrition based domain name and write a different article for each or would the better approach be to make one single landing page with a targetted domain name and the clickbank code?

Thanks for any help/tips you can provide!