Data Append Services for Better Seller Targeting

[Jonathan C.]

Hey guys- which data append services if any have you had success with and what types of data have you used to better target your direct to seller mailings?

Example- I have a free and clear list and am planning to get age and income data to target 55+ sellers with income in lower 1/2 of the distribution, but not sure what other factors I might also want to add into that to be more targeted. 

What types of income, demographic, etc data you guys have used successfully when targeting prospects?

And do you have certain data append services you've had good success with?

I searched forums but didn't see much on this topic. Thanks All