Well, setting up an online store would certainly be an option to consider if you are already in the retail business. But if you want to make an online business successful, it would require more than just setting up an online presence! Some form of online marketing would need to be in place, otherwise running a "dead" online store will simply incur most cost and time for you.
Moreover, online stores don't necessarily work for all types of products. Certain products (e.g. furniture), where consumers prefer having a hands-on experience before purchasing, would attract more sales if you had a physical store front instead. Nevertheless, it seems like the online retail scene has been growing rapidly over the years and it would definitely be a good idea to maintain an online presence these days.