It all depends on which region you are in, how many other people are doing the same, and in my case, which device you're on (mobile or tablet - if they run out on one I log in on the other and can usually find a few more).

I can usually get enough free videos to recondition my playing XI between closely scheduled matches and do a bit of morale boosting, but sometimes they run out part-way through and I have to use packs and farm back the missing ones later on...