I found out about this by getting an email from them through their newsletter email club that I signed up for as discussed in my previous post Saving at restaurants #2- birthday & email club discounts
I've been to Buffalo Wild Wings once or twice and I liked it all right. But your mileage / tastes may vary.
If you dine there enough, then its an easy way to get $5 off a meal. If I read the fine print right, it looks like the deal lasts until June 15th. Also the fine print says the $5 certificate is redeemable only on subsequent visits at the same location and you can't get the deal through online gift card purchase.
For more ways to save at restaurants see my previous series: