I almost fell prey to one such ad. A friend asked me to buy him a communicator device that came in two modes that were poorly differentiated. The seller wouldn't answer my emails about the differentiation and the contact number was not valid (one digit short). Then I googled said product only to to find that:

(1) The device was a kickstarter project and obviously wasn't ready for sale https://www.indiegogo.com/projects/cosmo-communicator#/

(2) The device was being offered for sale on many sites e.g. https://store.planetcom.co.uk/products/cosmo-communicator

I reported to Facebook but no action was taken as far as I could see.