There is alot more to adserving then just the ad being there, it has alot more do with who is seeing the ad. If you ever try Affiliate marketing you find out that you need U.S, U.K traffic for conversions alot of the time, specially if you are promoting it with cpm or PPC. Which makes sense why Adservers use geoip, becuase alot of the banner creatives and ads you see are someone promoting a affiliate product or service like Mate1 for example which only excepts U.S, CAN and U.K. So adnetworks are not going to give any publishers good money for international traffic becuase the advertisers don't want it.
I still don't get what video your talking about? Are you just talking about Veoh being banned or a video on there?
Veoh had restrict accessibility of their site from 100 ++ country, maybe to focus on more profitable visitors and to control their bandwidth .
Veoh.com is using Geo-ip and blocking poor countries. Most likely becuase of the Ads, there not getting money from the ads and videos uses big bandwidth so there blocking them.
after reading around veoh forums, few countries just got unblocked We have these message for blocked countries: