Ask HN: Paying commission on SAAS subscribers

Hi, I have a SAAS website in the works. Someone with a business in the vertical I am targeting has suggested they could help us out signing people up. Send out an email to their mailing list for example, mention our product in their conference booths etc Our service will cost customers between $30-$150 a month. Does anyone have experience paying commissions for people to get you subscribers / members ? Do the commissions continue as long as the sign up is a member ? Meaning, if you agree a 30% commission, would that be 30% every month for the life of the customer ? What sort of commision percentages are usual ? Any tips or guidance appreciated. Cheers