Home > Setup (Content) > Manage Products > Featured Products
New in v10 - we have paid attention to products that cannot easily be purchased from the home page, and yet have been selected as a featured product AND "FeaturedProducts.ShowAddToCartForm" is set to TRUE. In particular, this is true for Products with required text options, and products which have a conditional 'show buy button'. We don't remove them - instead we elegantly replace the 'buy' button with a 'details' link and send the shopper to the product page for more information.
It remains true that 'requires registration to view' products should not be used for featured products.