UnderMine

After buying the loyalty program from the shop keeper in one of the stores for 1200 gold which will get you the achievement A Loyal Customer, a Pilfer shop will unlock in your hub. You will need to buy all upgrades at all 3 tables for this achievement to pop. It's pretty straight forward except this achievement can be glitchy.

If you fully expand the shop and the achievement doesn't pop, you will need to start a new save buy the loyalty program and start expanding the shop on that save. The plus side is it will start adding to the progress you already have towards the achievement. I was at 50% when it stopped counting but most people I've seen where at 88% so just keep buying upgrades and it will eventually pop.

If it stops adding progress again you will need to start the last save slot and rinse and repeat. Hopefully that doesn't happen but this is the only way I've found around this glitch.

Good Luck!!