ummmmmmmmmmm because they're different shapes and sizes than what you already have?!
oooorrrrrrrrrr because they can be used quicker than a cricut and you can get just one rather than the whole tiny tabs set at once?!
Although, that last reason is lame because you can cut a little piece of paper to get just one cut out of the die, but still, by the time you do the cutting and lining up and sandwiching and rolling, you could've already cut 10 with your new punches.
I made sure to buy a cricut cart with tabs. Then I had to buy the spellbinders tab set because it was on clearance. I just saw these and I want these also!! I wish I would have seen these first! It's just easier to make a punch then get out a machine..... I keep telling myself I will not get these punches.... But I doubt that I will stick to it!! So I say lets punch on(: