SAS Link, Lufthansa Cityline, TAP Express: Why?

[jensdad]

At risk of sounding like an old stick-in-the mud (well, I am 50, and left the logistics biz 11 years ago): Why do so many airlines have 'regional' subsidiaries (normally with buzzwords such as 'City', 'Express', 'Link') that do exactly the same things as their parent companies?
I get that it can in one or two cases be for jurisdiction reasons - e.g. Emerald UK are able to operate domestic UK services while Emerald are not - but I see now there's a new SAS subsidiary called 'SAS Link', based in Copenhagen, i.e the same place SAS (the proper one) have a base.
I've heard that BA Euroflyer (sorry to labour the point, but do proper BA not 'fly' to 'Europe'?) are basically an exercise in taking on new staff at less generous T&C's than staff at BA. Are all of these subsidiaries just as simple/cynical an exercise as that?
I find it hard to believe there's any marketing advantage - no TAP punter will believe that just because his plane has the word 'Express' on it, it's going to fly any faster.
Looking forward to hearing your views...

[VickersVicount]

aren't lots of them due to cheaper non mainline contracts? TAP Express is Portugalia and BA Cityflier on different contracts.

[SWBKCB]

Yes, it is as simple/cynical as that. Money.

[BA318]

Cheaper contracts basically. In the past there were some subsidiaries which were created to operate to other places like KLM Asia or British Asia Airways so they could fly to Taiwan and China. Now almost all of these carriers are created to operate flights on cheaper contracts with different crew arrangements.

Some are also formed to be a brand name for several smaller operators operating on behalf of the mainline carrier for example American Eagle or Delta Connection.

[jensdad]

Thanks all, I did suspect it might have been a cost-cutting thing. However, knowing the marketing industry's ability to make money from things that nobody knew they needed, I thought that might have been a factor as well.
I guess the thing that made me wonder is the fact that it's always the short haul 'bits' of an airline that have these subsidiary identities - the concept of 'mainline' vs., well, 'non-mainline' seems to be a newish one. Seems to give the impression that LIS-LUX (op by TAP I believe) is somehow more 'important' than LIS-HAM (op by TAP 'Express').