one to three month’s salary Advertising diamond engagement ring according to the BBC http://www.bbc.com/news/magazine-27371208 Such rules are hokum ix month's salary De Beers started running an ad campaign campaign by diamond retailers BBC De Beers started running an ad campaign contained diamonds De Beers ad campaign three months' salary rule To make men spend more BBC News according to the BBC ix month's salary De Beers started running an ad campaign 80% of engagement rings De Beers started running an ad campaign BBC News only 10% Advertising Archives BBC BBC News s only 10 percen ix month's salary t excellent, excellent marketing strategy s BBC News http://www.bbc.com/news/magazine-27371208 That was another ad campaign by DeBeers BBC News s two months' salary two months of his salary