It's the new, exciting thing to do. You get full value when you pay to publish your ad or write-up in this program. What you pay is the general price for placing an ad on line in a good location where it benefits from promotion. That is good advertising value. Your gain from this program depends on the traffic to your site.
Every site needs something extra to draw sales and make money.
They are Impulse Sales Items. They grab the visitor and pull in extra money.