Featured products aren't really populated using the hometopintro topic. They're actually displayed below whatever HTML you have inside that topic. The template stacks them.
Not sure which version you're on, but in ML8 you have to create a new category (mine is called Featured) and map your featured products to that category. Then change the appconfig IsFeaturedCategoryID to the ID of that category. At that point your featured products should start showing up below your hometopintro HTML.
If that doesn't do it there may be another issue causing problems, but without more info on your version and exactly how you're trying to setup featured products, I can't offer much more help.
Running: AspDotNetStorefront ML 8.0.1.2/8.0.1.2