The ads for packs are not working at all on PC/Laptop, however you can still use them on Ipads / Iphones etc...

There is one for the Evil Dead, or the Walking Dead (Not sure which one) that plays on the phone that does not credit, regardless of how many times you watch it or what you do, but other than that I've had very little problems with other videos.

Im based in the UK btw, so it WILL be different to you if you are in a different country.