Is this a black-hat strategy? If so, what category does this fall under?

[FPD_NYC]

I am working with a major beauty client who owns an exact-match domain name related to their product that brings in a ton of traffic. They offer great content on this website that is inherently valuable. The catch is that the call-to-action brings users back to the main company site (a different URL). So if they want to "buy the product" or "learn more," they are taken to a different domain (the main company domain). There are 47 links to the main site on the EMD site.

There are some slight mentions of the main brand on the EMD site, but it's hardly noticeable. It mostly appears to be a standalone site not affiliated with a major brand.

My gut tells me this is black-hat but I can't find a fitting description of this strategy online, and why they shouldn't be doing this. Is this considered a doorway page / doorway site? Is this considered a link scheme? What would you call this strategy? Or is this actually not even black hat?

[GlobeRunner]

This is typically called a "microsite" and is not a black-hat strategy at all. It is more of a marketing tactic--to build a good, quality site with lots of content on a keyword rich domain name. Typically, many companies will purchase keyword rich domain names and not use them, they will just redirect them to their main site: like the way Books.com redirects to Barnes and Noble.

If the microsite only has thin content and doesn't have quality content, it could be considered a doorway page or doorway domain--but if it does have enough quality content on it then it would be considered a microsite. It still needs to have a good amount of quality links pointing to it, as well, in order to help the other site it points to. But, if the microsite is working, then the main brand site doesn't necessarily need to rank well. It gets its traffic from the microsite.

[MoosaHemani]

spot on Eric!