Sticker vending machine regrettably not included, though your nearest pizzeria might have one for you to look at. 

This official Pizza Tower sticker set was designed by Liam S.G. and includes 8 die-cut stickers measuring between 1.8 and 2.5 inches tall. 

Caution: Remove backing with care to avoid peeling the design off the paper. Ensure you grab the correct layer so the adhesive back is exposed.