There are some Samsung specific things like Samsung Apps that will only work if you own a Samsung device. Samsung Apps is a second "Play Store" type thing, and I suspect that Samsung could potentially put some things THERE that we would get for free as Samsung customers that you couldn't get elsewhere. Now, at THIS point I don't think any paid apps are free off Samsung Apps, but it is possible there are some.
One thing that is a bit weird about Samsung Apps is that EVERY version of the Samsung web page EXCEPT for the version for the USA mentions Samsung Apps. Check out
Mobile Phones | Televisions | Notebooks | Refrigeration - SAMSUNG AU and then check
SAMSUNG UK - Home Electronics | Home Appliances | Mobile | Computing or from ANYWHERE other than the USA version. Now, check the USA version and notice Samsung Apps is missing from being mentioned. It is possible that Samsung Apps will be a way to circumvent us being locked out of content due to the region we are in, or just for other promotional things. Registration would be another reason for using the Samsung account.