True, but it doesn't have to have as large a reach, because it's presenting a more consistent anti-vax opinion. An anti-vax post on a FB newsfeed is quite lik

True, but it doesn't have to have as large a reach, because it's presenting a more consistent anti-vax opinion. An anti-vax post on a FB newsfeed is quite likely to have counterarguments. An anti-vax website is unlikely to run into such problems. And going back to the original post: does "vaxxers on FB, anti-vaxxers elsewhere" sound like more polarisation, or less?