> By what other means would people with a product or service to provide reach other people who are interested in obtaining that product or service?

In my opinion, it would take quite a lack of imagination to ask such a question.

There's many many ways to reach people who want your product. Industry-relevant news publishers and conferences, professional/personal anecdotes (eg, blogs and recommendations), demonstrations and training offers, etc.

A different question would be: by what other means would businesses force their products on people who don't want them? Hopefully the answer is: none.