The old Ondigital did things that way
http://onhistory.co.uk/ondigital
Of the general channels, any 1, any 6 or all
Of course, originally, the Sky multi-channels were free with anything else.
Come to think of it, why ARE we paying for channels with adverts, and surely advertisers won't pay much for ads on a subscription only channel where programmes may score next to nothing (like one program that moved to (don't) "Watch").
Until 100% digital switchover, the old 5 channels still have the highest presence.
Next most important has to be Freeview, since most new TVs are equipped with freeview, it IS the system which succeeds analog, as with any luck, it's plug and go.