I registered for a DUNS number circa 2003 at no cost, and also experienced high-pressure sales calls/emails regarding upgraded credit monitoring services. One sales rep even mentioned 9/11 as a reason that I should care about my business's credit rating. That's pretty scammy as well as pretty stupid. If you actually want to do business with the government, then you'll also have to register your new DUNS number with the CCR, and ORCA, which are much more time-consuming processes, but not at all scammy.