I’m not usually one for these sorts of discount websites, but since I actually made use of one, I figured I’d share.
I’m probably the last person to jump on the Group-on bandwagon, but I originally signed up hoping to get some restaurant discounts. Unfortunately I haven’t made use of their service yet as most of the vouchers seem to be for things just outside Maastricht. I have, however, seen several vouchers for driving lessons (which can be quite expensive here) and for more expensive things like Lasik eye surgery. Groupon’s Dutch website is in Dutch only, but you can use Google Translate to get an approximation.

I actually purchased and used two vouchers through SocialDeal so we could go out to high tea. I’ve been more impressed with their offerings as they tend to be more Maastricht specific. Since I’ve only been following this site for a week, we’ll have to see if that trend continues. SocialDeal’s Dutch website is available in both Dutch and English.
Tell Maastricht to keep funding Crossroads Magazine.
I always go online to check the supermarket/Kruidvat sales before I leave. Much more accurate, and no nasty surprises!