Well it's not self serve, but I had a Birthday promo through my Club Mango card for $5, so basically free froyo for me. The Club Mango card is their rewards card, free to sign-up.
Usually the non-self serve locations have limited flavors, like only 4. The froyo is served in 3 sizes and they also make smoothies. They had Original Tart, Pomegranate, Madagascar Vanilla, and Nutty Potion No9. I went with a medium nutty and topped it off with a lot of fruity.
The staff working the counter was very friendly and chatty.