Which advertizing you choose, depends on how much time you have and on how much money you have.
When using FREE ADVERTISING, you will spend a great deal of time searching for places to place your ads, and you may have to spend money for paper, ink, cards, etc...
When using PAID ADVERTISING, you spend a great deal less time. Whether you choose S-Builder Co-op, or another ad agency, you will generally have a better response than posting to safe-lists.