They are targeted, typically at the cardholders who stuffed them into a sock drawer. Discover really pushes you into trying to make it your "go to" card. When you call to activate it, they really push that on you...asking you why you don't use it much, asking if you'll use it more. It's pretty funny. They aren't too pushy about it, I guess it just sounds corny to me. Make sure to tell them they were sock drawered because of the .25% cash back until $3k spend, I always do.

These offers vary in amounts. $500 is the largest I remember seeing. I take advantage of all the little bonus offers they send me...set something on autopay, 2% cash back for a day...whatever. It's like signing up for a new card bonus without taking the credit hit. Find a way to hit the spend, plenty of creative ways to do it.