Once upon a time in Tuscany, a winemaker learned that a large number of his wines were being sold in a peculiar, much overlooked part of the United States. The middle of Texas, of all places! Intrigued by this far away land and its people - who so obviously enjoyed his wines - he set off for a visit.
With two compatriots, he visited the restaurant in Texas that was responsible for the bulk of his sales. They sat in a quiet booth in the back and sampled some other bottles on the wine list from reputable Tuscan producers. They feasted, and racked up a bill over $400.
The winemaker paid. He left $40 as a tip for his server.
Just under 10%. For excellent service.
The winemaker didn't seem to realize that the reason his wine was selling so well was not because of the importer who brought it to the States, nor the distributor who picked it up, nor the sales rep who brought it to the restaurant's wine buyer, nor the wine buyer for putting it on the list.
The wine sold as well as it did because the servers liked it, thought it was a great deal for such a well-made wine, and emphasized it to their guests. The people largely responsible for his success were the very people he had slighted. The servers, thereafter, boycotted his wine and the winemaker saw a dramatic dip in his sales. Had he never left Italy to investigate, this might never have happened.
The moral of the story is: Better to let sleeping dogs lie.
Oh, no wait.... it's LEARN TO TIP, PAISAN!