We don't have the year-round humidity they have down south so people aren't getting washed very often. Everybody has gutters and they're almost always white, they also get dirtier faster than the house does. Most people are amazed at how nice the gutters turn out at the end, originally thinking they would have had to paint or replace them. On a small or medium sized house the complete wash would usually be around what new gutters would have cost alone. Most of my business is referrals and the gutters are at least 50% of what drives that even though I will never do just the gutters.
People like bright shiny things.