Whoosh will gather customer data from viewers responding to competitions and requests for further information on C5 programmes such as House Doctor, Hot Property and motoring programme Fifth Gear, which launches next month.
It will give this data to the broadcaster and brands providing programme prizes, and resell it to direct marketing agencies.
C5, which is five years old this weekend, will also use Whoosh to help it emulate newspaper brands' white-label initiatives such as The Sunday Times Wine Club.
C5 is Whoosh's launch client, but it will also approach other broadcast brands.
Analysis, Page 15.