they make big money because they have many hubs before HP was slapped. i don't want to give any details, but i know them personally n.. ok, i don't want to discuss anymore. if i were u, i will just use EZA to funneling traffic into my landing page or it's better you have ur own domain and redirect that domain to sales page.
do u know the concept of 7 page views before buying? based on several online marketing researches, users will buy after reading around 5 - 7 pages about that subject. and after adapt this concept into my marketing, yeah, huge increase in hops and sales.
if u want my opinion regarding to landing page, squidoo is better than HP bcz visitors will not distracted by other articles' link. IF U DON'T WRITE GOOD CONTENT WHEN USING HP, USERS MAY GO TO ANOTHER ARTICLE THAT SHOWN ON THE RIGHT SIDEBAR.
bum marketing is the way to go.. send article to eza, ga, ab, buzzle, press release, hp but use squidoo as your landing page. make videos on YT, metacafe. why don't dominate the first page on google? think big. one article is not enough. u need to increase ur visibility n this can be done by dominate the first page.
it's all about hit n miss. if u don't make any sale, you just loss ur time.

link wheel ur web 2.0 properties. i had done this too many time. eza is the best choice.