Amazon is selling $40 smart plugs for $20, and shoppers say they 'do not go offline and are quick to respond'

TheStreet aims to feature only the best products and services. If you buy something via one of our links, we may earn a commission. With the power of wi-fi, just about anything can become a smart device. We've got smart toasters, toilets, mirrors, and umbrellas (among many more). And now, with the…