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?