I've been to a few jobs, where the people have been to the biggest tile suppliers and some, (NOT ALL) haven't got a clue on what they are selling.
1. customer bought natural stone, I go to look at her job, talk her through everything that's needing done, i.e cement based adhesive's, prime walls, seal the tiles, they will eventually need sealed again in roughly 2-3 years time as they are a natural product and they require maintenance.
Customer didn't know any of this, had been sold BAL GREEN STAR for a 40x40 travertine bathroom as it was the cheapest and no mention of needing to seal these tiles.
2. Last week a customer had been in picking tiles from another well known tile supplier. Had picked out 80x80 porcelain tiles to go on the existing plastered walls, told her she may not be able to do it, due to the weight of these per m2, but I'd go down and ask the necessary questions and get her a discount.
Guy in there never had a bloody clue, what I was on about. Looked at me like I had horns coming out my head, when I was quizzing them on everything.
10 mins later, I left with not 1 of my questions answered as the guy just didn't know. Said he would ask his boss to phone me, and I'm still waiting.
The people selling the stuff, should be put on some sort of course as well.
I get it's their jobs sell stuff, but they are just trying to get stuff out the door.