In the UK, carriage on Sky Q will give the new service the opportunity to prove its worth to viewers. Without integration with the UK's biggest pay-TV platform, growing scale is difficult for nascent DTC services.

Elsewhere in Europe, Discovery seeks to bundle too. Unlike the US, where the company has a single model—basic cable—in Europe it operates both free-to-air and pay channels, and it also owns Eurosport.

Ultimate success will come down to whether Discovery's "real life content" is essential and defensible. Generally there is little evidence of people taking services that are not broad, while the barriers to entry for competitors wishing to commission "real life content" are lower than other genres.