Selecting by Household Income allows you to find potential customers by their estimated income ranges, in increments of $10,000, starting with Under $20,000, and topping out at $500,000 +.
Marketing by Household Income can be useful.
For example: If you are a travel agency that wants to market an expensive vacation package to households with a large household income level, this selection will provide only those contacts.
This is closely related to the next consumer criteria – Personal Finance /High Tech.