Example: skin care website, they sell women's beauty and anti aging products. Their demographic is 15% IE8, but you know who are most likely to buy their products? Mature women, who are also more likely to be the ones in that 15%.

The next part of that puzzle was when they launched into China. China has a huge population still on XP and IE8. Literally millions of uniques from IE8. We even had a percentage from Netscape!

Fortunately the agency handling them was smart enough to research the demographic in both instances, but many agencies won't. They will brazenly force their opinions on their users who frankly, don't give a crap how you feel. They just want it to work so they can buy stuff.

You have to view every hit as a customer. Imagine if Walmart stopped letting in 15% of customers.