Our not-for-profit did a fundraising event with Proshred, getting the word out to the community that they could come at a certain date and time and shred as much as they wanted for $10. That was an arbitrary amount, but it worked for us.
It was such a hit that even after paying the fees for Proshred's equipment and service, it was one of the most profitable fundraisers we have done...and we only did it for two hours.
The Proshred team was easy to work with and engaged positively with the people coming to the event. Easy five stars.