If there are enough of bitcoin users, the retailers can not ignore such a large customer base. In some of the fields of industry one can expect bitcoiners to be a very numerous group of people. For example, to sell a product that requires a high IT skills to use, in my opinion should address the ability to pay for it in bitcoin, because its almost sure that people with high IT skills knows about bitcoin and probably use it. The other fields could include financial options. Even game industry should be more incentivised to include bitcoin payment, because bitcoin users prove they have enough free time to learn new things, so probably have time for electronical entertainment.

So to answer the topic, there should be a constant asks about, if such a payment in bitcoins are available, to make retailers aware about the customer base.