@SharonA
//My Dad is 91 and how is converting gonna help him or them????//
They'll have to work quickly, if they want to get him to bequeathe them some dosh.
They are the three dimensional equivalent of spam email. If 1 in 100,000 visits nets them a few thousand pounds then it is worth their while. They're doing it on a voluntary basis but, to the organisation it is a zero-cost money harvest.
Might be similar with the Mormons and more than once I've had American accents at the doorstep, so they're not exactly short of funds, either.
Since neither group asks for money at the doorstep (laws against doorstep sales now, iirc) then there must be some other way of turning a buck.
Some account of their charitable works, in the "3rd world" (deprecated, un-PC term, these days, I gather) would make interesting reading. You can't eat copies of The Watchtower but they might make a dozen spills each.
;-)