The Who, Where, What, Why, When & How of mailing is:

WHO do you want to target?  Self employed people, businesses with 1 to 10 employees?

WHERE:  What area?  Zip code?  city?  area of town?

WHAT do you want to inform these people of?  (content of mailing)

WHY would they want what you offer?  (what make’s YOU better?)

WHEN do you want to solicit them?  (is there a better time of year?  season?)

HOW do you want them to respond?  email?  phone?  response card?

Also, If you would want to just target a segment of a zip code to all residential and businesses, there is an alternative program called Every Door Direct Mail that does not require purchasing a mail list, and the postage is cheaper (.183 cents each).  It’s the most inexpensive way.