See the button in the bottom left corner, with the shopping cart? This is the store!
Tap the shopping cart button to see the current promos in game and to buy currency, decorations, chests, or guano for your farm!
You can refresh the limited time section to find more deals! But be careful as the cost for doing so increases every time to a maximum of 200 Potbucks -- Once it's at 200 Potbucks, it'll remain at that value for 24 hours!
Promos are real money offers! These change frequently and are time limited so get them while they're lit, bud! Promos also tend to coincide with your Karma Contest tasks so remember to check them out every contest for that competitive edge!