I don't like that everybody can buy Shark at such an enormous rebate that has been the case lately, it is undermining the value of the program and the reason for anybody to pay the full price, since one would tend to think that this offer will come again some time next year. Also those who just happened to pay much more just sometime before the offer came along will feel very much ripped off.

Instead I would like to propose another kind of special time limited give away offer scheme:

If a Shark user, say having to be at least a one year registered user, would like to recommend the software to someone.

That person could be offered the software at a substantial reduced price, offer valid for 2 weeks.
He/she should receive a dedicated email from PunchCad with a Rebate Code stating "On behalf of the registered owner and experienced user Mr. Mike Andersen we forward his personal greetings and recommendation and are pleased to offer you Shark with a 50% rebate. This rebate is valid for 2 weeks only and is the experienced users once a year opportunity give away offer"

Alternatively the experienced user should be able to give away a license only paying 50%, leaving it up to him to give away or get the money from the new user.