During the advent of digital technology, few theatres bought digital projectors. When others hesitated, DSPs came in and offered the equipment for free. When asked what they wanted for return, they asked such owners to sign on certain documents and write off the ad revenue to them. They also offered to share the ad revenue after the projector overhead costs were met. At that time, ad revenue wasn't that great, so theatre owners did not think much about it. Now, after a projector is installed in a theatre and even after a decade after its costs are met with VPF as well as ad revenue, VPF is still being paid to the DSPs. that too higher amounts than before.