whats the cheapest way to send out postcards?

hey everyone,

I'm starting to send out postcards without any companies sending them for me.

i figured this way it will be cheaper..

i have 5000 postcards that i printed and I'm trying to figure out which way will be the cheapest to send them out to my list. I'm not sending them all at once i will probably send the same list couple time.

anyone have an idea or knows? i saw something about a bulk permit with usps but have no idea how much they will charge on each stamp..

please let me know what you guys think.

thank you for your help, Danielle.