That depends on the content of the other site. In your case it leads to site which advertises and offers a item by using referral marketing. Your intentions, why you do so, are clear. Imo referral marketing nowadays is very suspicious and not trustworthy and something to stay far away from. Take a moment and read their "Terms of services".
The most important parts of it:
[that site] reserves the right to change its Terms and Conditions at any time, for any reason, without notice. We also reserve the right to change the methods through which free items are earned.
By registering for an account on [that site], you agree to receive any 3rd party messages that we wish to send to you. Including, but not limited to, 3rd party advertisements and offers.
So after you registered, they can spam you with any advertisments they want, even if you don't want to.
Now the name "Stargate" along with some ad or linking to some ad, is dangerous buisness. MGM owns the name "Stargate" and they can sue anyone who uses it in order to advertise something to make profit. That site you linked says their item is for free (non-profit), but the items of the following ads aren't. It's like a chain: first link is the name "Stargate", second that site you linked, third link are ads to make profit. I don't know if MGM has the right to take action against this in this case, but imo it's not worth risking. Something like this has already happened once to a german OFP news site. And this is the reason why you hardly can find anything about our stargate mod on the ofp/arma community sites out there.
Better take it off. If you don't, I'm pretty sure one of the admins will do
