To find out which service will work for your business, sign up for one at a time, and poke around in the areas relating to your product or service. The fundamental operating principles of all online services is to offer a place where people can find helpful resources . Blatant self-promotion is prohibited. Any message containing only sales information will likely be deleted by the system operator. Each service has its own rules regarding the listing of prices and phone numbers, so read these rules before you start marketing.
All commercial services provide areas for marketing information.
This is the only area you can place overt sales information. The price of placing an online ad is anywhere from reasonable to free, so give it a try. Keep your ad between two to four lines. List an offer-special pricing, free samples, and so on. These are meetings of people with similar interests or businesses.