ZydoSEO - 7:02 pm on Apr 19, 2013 (gmt 0)
This is no different IMO than your company offering a scholarship to college students majoring in a field related to your business and having a government education-related site decide to link to your scholarship page on their student scholarship resources page.
You're getting the link from the government site. The government site is in no way benefiting from that scholarship (or in your case, from the discount).
Personally, I see nothing wrong with what you've described so long as the site where the link is placed (or any other site/business they own) is not receiving payment, favors, etc in return. If this were an issue, then every coupon site and mom's "saving" site on the web that posts links to deals they have found would be in hot water.