Just checked... In Canada, only 5 digital stations are broadcasting in VHF-lo (channels 2-6), but about one-third of digital stations are in VHF-hi (channels 6-13). In the U.S., there are lots of VHF-hi stations, but very few VHF-lo.
In either country, to get almost all the stations you need to cover the high VHF channels, but not the low VHF channels.
I should have said that it's the evolution of the original coathanger homemade one. The homemade one had 4 elements also and I added a sheet of aluminum (some use foil over cardboard) as a reflector. The commercial one uses tubes as reflectors and is very light. It collapses and is easy to store.