Antennas Direct is more of a "name brand" antenna offering a range of indoor / outdoor antenna equipment for your TV. They certainly are more pricey than other generic or Chinese antennas found on eBay.
There are a host of generic antennas for sale on eBay that would only be good for very short distances. Antennas Direct offers antennas ranging from 50 mile distance up to 70+. It would even appear they have better overall construction than say a generic/unbranded antenna.