A two-step offer is a marketing tactic also called a lead generator. It is a tool that can be used to get a potential customer’s information for a sales pitch later.
A two-step offer in an infomercial requests that the viewer call a toll free phone number (i.e. 800/888) and ask for more information (video or brochure), rather than purchase a product or service directly. They are considered a lead and pursued via mail, email, or phone for the actual order.
This gives a company the opportunity to create a longer, more nuanced sales funnel than asking for an immediate purchase. This can be extremely helpful not just for higher-priced items, but for items that are part of a larger collection.