Content Aggregator – (In terms of Interactive TV & VOD) – Content collector and often distributor to network operators who then offer it to their customers. IN DEMAND is an example.  In terms of the web this can include search engine portals that collect and offer content, such as Google and Yahoo. http://en.wikipedia.org/wiki/Aggregator

VOD/PPV Content Aggregator – (VOD Aggregator, VOD Aggregation) – Collecting programming that will be offered via pay per view and/or video on demand. Perhaps enhancing, packaging, encoding, asset management and/or transport to video service providers is also (or partially) provided by the Aggregator. http://en.wikipedia.org/wiki/Aggregator

Subscription-based Aggregator - Fee-based membership portals for specialized content. The content may be collected from members, from third party providers looking for an outlet, etc. It's growing in popularity due to Internet TV/IPTV. For examples see The Internet TV & Business Index™.

Visit the ITV Institute for more information.