I use postal methods a lot for one of my websites (postsecretcollection.com <- Shameless plug). But they are a tad expensive on the postcard side if you ask me

I use postal methods a lot for one of my websites (postsecretcollection.com <- Shameless plug). But they are a tad expensive on the postcard side if you ask me. I just want to know how they get the price down to just 99 cents.