Samacsys seem to be another one of those companies that perceive there is a need for quality data, spend a lot of time creating it, then discover there is actually very few people willing to pay for it.
However, the people who are willing to pay are suppliers who get referrals, so that provides one avenue. Then it is just a question of getting as many users as possible by offering at least one level of "free" service. Octopart, Snapeda are in similar game.
Other ways to monetize are adverts, collecting data about users, customers paying for "express" part creation service, tiered subscription fees, deals with EDA companies (Zuken in this case). I always wonder about the revenue source, often they either end up charging subscription fees, or go bust, so I find it best not to rely on them too much.
I haven't used their service but the problem with all these "free" services for me is that they retain rights to the data, and as I often publish open source projects I don't want to get proprietary stuff accidentally mixed in. For purely private or commercial use that would not be a problem.