Sorry to swoop in on this, but I just went through
Post# of 75002
Thus a different label and in many cases, brand, is used on amazon than in other channels. It is very likely that it all contains the same stuff.
If they use an isolate, they can achieve higher concentrations of CBD, but it is only CBD and other cannabinoids are lost. It is more water soluble as an isolate and can be advertised as 0% THC.
Sorry if this has already been discussed or if I missed the point.