As a filmmaker, getting your movie into the various VOD marketplaces takes way longer than it should. The reason for this is simple. Every platform including iTunes, Amazon, NetFlix, Hulu and The Watchbox and Chill all want great content.
The delivery standards required by some of these platforms are so high, that if even one frame is messed up, your title will be rejected! This is why video aggregators work with amazing encoders. With a reputable encoding company, the encoders will do their best to fix any hiccups in your source. In some cases the encoders are successful. In many cases they are not.
In the event your title fails QC, your source (usually a portable hard drive) will be returned to the filmmaker in hopes of getting things fixed. This obviously delays the process significantly.
So my advice for VOD submission is this: Follow the specs provided by the aggregator. This will save you time and potentially money. And if you are asked to deliver your title via Hard Drive, the one that most encoders endorse is the LaCie Rugged All-Terrain Hard Drive.