The answer is going to be, how many houses do you want to buy? If you want to buy 1 house a month then we think you should buy 500 leads. Even the best mailers and callers will average a 4 percent response rate. An average close ratio for the business is one house in 20 leads. (By the way, 1 in 3 of those sales will be at the appointment and the other two will be in follow up). Do you have a better conversion ratio?