Saving up the large purple monsters?

I'm going to agree with everyone else, you earn monsters quite fast. Also, you get more crafting materials if your friend clicks on them instead of dying after 4 hours. I tend to sprinkle all the friends I can (many of them can't accept more) during my normal friends visit giving a few more to lower level players. Then when someone sends to me, especially when I see it drop, I send more their way assuming they are currently online and can get the benefit from them.