Hi @CreativeCrafts , welcome onboard!
Snail Mail Friends has two swap methods; 1. Regular and 2. Special
Regular Snail Mail is always without goodies, will fit in a standard envelope, and can be considered flat mail.
Special Snail Mail is always including goodies. This is mainly because the type of swap implies that goodies are enclosed. For example, when you make a flipbook, you tuck goodies inside the pockets.
The Xtra goodie option is when you choose to send each other extras. Communicating with your swap partner about what kind of goodies you want to exchange is always a good idea.
I hope this explains it to you. If not, let me know.