Why is Listsource not showing all multifamilies in my target market?

[Scott Lennox]

Hi everyone.  I'm assembling a Listsource list for a small marketing campaign and encountered a problem:

When I ask the site to narrow the properties in my target community down to only the 2-4 unit buildings, the number of it kicks back is far below what I know to be true.  Also, if I ask it to select only duplexes, it says there are zero (same for tri and quad properties as well as multifamily).  

Do some areas list the number of units on a property differently than others, making Listsource generate inaccurate and incomplete lists of multifamily units.  How can I ensure that I'm not missing large amounts of multifamily properties in my campaign?

My target market is coastal Monmouth County, NJ communities, focusing on Asbury Park.

Thanks for your help.

-Scott

P.S.  I love this site.  It's the most honest, positive and helpful community I've ever encountered on the web.