A couple of years ago I was involved in the development of the site for a travel company here in the Netherlands. They focused on trips by car, which is a popular affordable way to go on holiday in Europe, so most of the destinations were throughout Germany, France, Spain, etc. Locations were rented by private individuals and this site was essentially a reseller for over a thousand of these from lodges to B&Bs.
Because this site had a pretty low turnover and wasn't able to really sell vacations for much more than the locations themselves charged, they depended on sales of travel and cancellation insurance. The initial design of the booking forms included auto-selected insurances and "extended insurance".
Both the auto-selection as well as the vagueness of the "extended" insurance didn't sit well with us, and we recommended not taking that direction, but the client essentially told us to build it that way anyway as their revenue depended on sales of them. We argued that if you're just up front about the quality of the insurance, and provide statistics or something about how beneficial it is to take insurance (which it is, especially if you're traveling pretty far and with a few people), they'd get their income but without pissing people off.
Today the form no longer auto-selects and includes pop-ups with more information on the extended insurances. They got enough complaints and enough overhead spent on resolving the problem that they made a design change, since all their support and booking resolution was handled in-house over the phone. For them to make such a far-reaching change (considering they complained that it was so important) suggests that the negative feedback was quite significant.
The whole thing reminds me of this quote: (bonus points if you know from what movie!)
My boss said I can take $100 off that Tru-coat!