well the aciai berry trial pretty well most cpa neworks have the trial
Right now I would be very careful with any kind of "free" trials. FTC and other Government agencies are massively on the hunt for any deceptive methods right now.
But if you promote a "free" trial within the TOS of the offer and the offfer itself has some fine print, it's on them. Right? Like a 'due diligence' thing or something?