Oh, that’s not the only issue at all.
It also completely eradicates your data allocation on a capped/throttled mobile connection, since high quality video is capable of sucking down 25GB in as little as 2 hours. The worst case scenario being that 25GB is the standard capacity of an HD blu-ray disk. Maybe at lower NTSC quality, some video ads only eat up the amount a DVD consumes, clocking in at ~2GB per one hour.
Put another way, if you completely buffer the same 30 second full motion video ad, 240 times, that advertisement has completely abused the data cap for your mobile plan.