Fit can have two meanings, when talking about shopping. - The clothes are the right size for her. - The clothes, furniture, etc are the correct style for her look/aesthetic. It might help to clarify if you included the next couple of sentences at the end, but I expect that it's the first one. Jules is talking about someone shopping online (laptop) and implying that if they're relaxing with a glass of wine they are quite likely to buy stuff (impulsively, I guess). However, they might not if they don't think that they will be the right size (will fit). He's come up with some way around this, I guess. Perhaps free returns, or software to help make sure you get the correct size, something like that. It could mean match their style. Although I think the size meaning makes more sense. Shopping potential is the liklehood that they will shop. If that type of person has a high / good / real shopping potential, they are likely to do a lot of shopping with them. He thinks that women browsing the internet at the end of the day, with a glass of wine, are likely to buy things.