How to increase Store Levels?

[SIM CRAZE'D]

Can someone tell me what is the criteria to increase your store level? It seems like I have been stuck at the same level for days now and i do help the employees with ringing up customers.

[cHeLeY420]

Your store level should be going up when ringing customers and when you purchase inventory for your store. It is only 5xp so it is a small amount.

[Mensantos]

You get 2 Storepoints for every Box you buy in the shop, and 5 points vor every Customer.

But you lost 1 Point every time a Customer can not find any item he want to buy.

normaly you should go slowly to the next level