The good news is that if you fall into that camp or are just curious in general about the general acceptance of Apple Pay, it seems that Apple has begun to let companies order decal stickers in which they can place it in their stores to let customers know that Apple Pay is supported. Apple will let companies order up to 5 decal kits at a time, via a dedicated website, which includes two glass decals in different sizes, two register decals in different sizes, along with an application tool.
Companies that need more than five decal kits can contact Apple with assistance. With these decals, it should make things pretty clear and obvious as to which store will support the feature, kind of like walking into a store that says they accept American Express, Visa, and/or MasterCard. Hopefully it will also lead to Apple seeing an increase in Apple Pay use.