I'm looking at doing something similar. I'm planning on providing beta users a significant free period beyond when I start charging, ie. a whole free year. Th

I'm looking at doing something similar. I'm planning on providing beta users a significant free period beyond when I start charging, ie. a whole free year. The incremental cost is relatively small and the goodwill seems worthwhile. I don't want to offer permanently free accounts since anything that is 'permanent' will be a pain sometime in the future! Always provide a 'sunset' clause.