I think it takes courage, because people will only pay if you provide some real value for them. Give out things for free and you might build a nice user base even if the offering is not so interesting.
Not necessarily; if you hook up people on free and have them invest time money or resources into your free by walled system, the cost of moving elsewhere overweight a small upcharge once you start charging.
Example is Twilio. They were first and we implement them very heavily into our systems. Currently our bills are at around $400 per month. Phaxio is much cheaper, but we just got used to Twilio and unwilling to spend time money and resources into jumping to something else just for the sake of little savings.
