The diamond wedding ring as a tradition was shamelessly invented by DeBeers to sell diamonds. It is probably the most effective and lucrative ad campaign for a consumer purchase in history.
It corresponds to ancient tribal rites. In African tribes, and other tribal societies, the groom had to pay a bride price by giving livestock to the father of the bride. This served the purpose of assuring that the groom could care for livestock and therefore, provide for the bride and the grandchildren, The exorbitantly expensive diamond ring serves the same purpose, as it demonstrates that the groom has either cash or, more likely, credit. De Beers shamelessly suggests that two months salary should be spent on the engagement ring. Most Americans, however, normally spend only a bit more than one.
Diamonds are grades from A through M, but it is very rare that the grade of the stone will be provided to the purchaser,most of whom know nothing about diamond grades. This is because the grade of most middle class wedding rings is rarely above D. Buy it for $3000, then take it to the pawnshop down the street, and you will be most fortunate if you get $200.
I can't say that this ad is particularly objectionable, but it probably will not be accessible for long. Such information tends to queer the deal when people might be looking for ways to avoid getting diddled by slick marketing.