The free market must enable all interactions; ironically this is more of an oligopical than free marketplace model since the free marketplace only functions at a high level of abstraction which means actor’s true preferences are often unavailable.

"In a capitalist society, all human relationships are voluntary. Men are free to cooperate or not, to deal with one another or not, as their own individual judgements, convictions and interests dictate." - Ayn Rand, Author