Here are some of the services you'll need to set up:
A CDN (Content Deliver Network) - generally you'll work with an established provider unless you have a seven figure budget - but even these need a huge degree of integration
Application Server - to run your video management system - preferably you'll need four of these in two different locations with load balancers in front of them
Database Cluster - to handle the data management; again, having two in different locations is ideal if possible
Firewalls - to stop attacks on your application and content
DRM Server - to protect your content and how it can be distributed; you might also need an IP resolving service for territorial control and geo-targeting
DNS Server - you'll need to control the naming and URLs for your service
Local Encoders - to encode your videos locally
Encoder Farm - for remote encoding and user generated video
System Monitoring - to ensure that your service is available and to alert of any problems
SVC - version control so that various staff can work on upgrading different aspects of the system
Issues Tracking - to log any client or user issues or requests
Player Servers - to host the pages delivering the web service; you may also need separate systems beyond the application server to host web services
Then there's the promotional website, support website and you begin to get an idea of how complex this can become.
And you still might need the studios and the edit suites to produce all the content.