Whereas WiFi got all the attention, powerline networking still has its uses. There are definite advantages to being plugged in, and not over the air for your internet connection.
Sure, wireless networks work well for some people, but there are some venues where Wi-Fi simply doesn't reach far enough to provide reliable service across your entire home. If thick or heavily insulated walls don't cut into wireless strength, there's a variety of household devices, from microwave ovens to cordless phones, that can cause radio-frequency interference. Neither is a problem with power-line adapters; as long as you have a spare AC outlet in a room, you'll be able to get network access there.