FNW might explain. In these instances I guess they have no incentive to provide offers or discount fares
The inter-available fares you refer to are the permanent, basic fares for that flow; there is absolutely nothing to stop any relevant operator introducing special offers and/or discounts in addition to these fares.
On the contrary; any operator who does set the fare has restrictions on introducing their own 'dedicated' fares, so if none of the relevant operators set the flow, that frees them all up to offer permanent dedicated fares if they wish. This is in addition to any temporary fares they wish to introduce.
But do they get a share of the revenue if they set the fare?
Revenue allocation ignores who sets the flow; it's determined by a system called 'ORCATS'.
There is plenty of reading material on this forum regarding ORCATS if you are interested:
Some previous threads that may be of interest:
LNW/WMT set the cheapest WBQ-CRE fare which is bizarre ... but handy. But Northern also do a CDR while there's nothing from Virgin.
If you can provide a link that would make it easier and avoid people having to look it up (also without looking it up, not everyone will know where these locations are); here is the link for the fares from Warrington Stns to Crewe:
http://www.brfares.com/#!fares?orig=WBQ&dest=CRE
There is a "Not via Manchester" flow which is priced by West Midlands Trains (and is issued from Warrington Bank Quay specifically), while the "via Manchester" and "Any Permitted" fares are all set by Northern (and are issued from Warrington Stations, so also valid from Central)
The fact that Virgin don't price this flow means that the fares might be more reasonable than would perhaps otherwise be the case
; it also means that if WMT ever do operate through services in the future, Virgin would be allowed to introduce their own dedicated fares at a lower price, if they wanted to (there is no point in them doing so at the moment, of course).
If you are interested in fares, you are more than welcome to join us at a free
fares workshop