Don’t Make Price Promises Unless You Can Keep Them

One of my pet peeves is misleading advertising.
In some cases it’s a matter of reading the fine print.
In other cases it’s simply a matter of the advertiser “chancing their arm”.
At present this site, and several others I run, are displaying adds from a particular company that claim to offer “the best”, “the cheapest” etc., etc.
Of course they don’t, but it does make you wonder about people’s buying decisions. Are they really influenced by a company’s own claims?
Should companies sell themselves as being the “best” etc?