1. It stands out from the crowd.
2. It's fun to create! One of the things I love about mail art is there are no limits. You don't have to create a masterpiece. Everything can be random so it's the perfect palette to experiment and have a little fun.
3. It's unexpected. We all receive normal mail, bills, junk mail etc. Receiving a little craziness in your mail box puts a smile on your dial!