If my video share website force visitors click an ad before the visitors can actually watch videos, is it against most ad network term of service?
don't do that.. off course they don't like that kind of fraud click. just imagine this ad network is yours. do you like paying publisher for no reason
Most advertising networks do not allow incentivized traffic or clicks. Asking visitors to click on an ad before being granted access to certain content is considered an incentivized click.