Ask HN: Free account for life for early SAAS subscribers?

lets say I have a SAAS where subscribers are professionals and can be found by consumers for their services (e.g. lawdingo to find lawyers, turbotax CPA select etc). To get the initial subscribers, what about the idea of not asking them to pay ever if they are the first 1000 or whatever users ? If the service takes off with those free accounts, wouldn't it be easier to show to the next 1000 potential customers ? If service never takes off, anyone we don't have to bother about next customers ? What do you all think ?