What impact did the Concorde have on business of other sub-sonic airliners? The Concorde was anyways a technical marvel of its time, and a status symbol for society. Its fares were well above the rest, costing USD2999 + taxes for a JFK-LHR journey. But, at the same time there are reports that British Airways indeed made $750 million from it, over 27 years:


  It was not that Concorde operations made losses. In fact, on an
  average Concorde made an operating profit of £30-50 million a year
  for BA. BA reportedly earned £1.75 Billion in revenue for Concorde
  services against an operating cost of around £1 billion during its 27
  years of commercial operation (1976-2003).


So, what impact did it have on the business of other sub-sonic airliners? Probably, economy class would not have been so much stricken, since its fares were more than 3 times higher. But what was the impact on business class travel of other airlines and airliners, between the destinations served by the Concorde?
A few thoughts:


The British Airways Concordes only operated scheduled on the London Heathrow- New York JFK route. This implies this is the route under the most competition. There has been enough pressure on this route even after the demise of the Concorde for several companies (as well as BA) to try business-only services on this route.
By experience, changing flights is never quick in the US since you need to go through customs and add time margin to ensure you make the connection (Think three hours connection time on the ground). I think even before the current security state you'd rather have taken a direct flight than change from a Concorde to a domestic flight if possible.
I don't think the charter destinations would have caused much impact on other airline operations.