A factor behind Air Europe's undercutting of prices while continuing to expand profitably was that it first waited for all the other operators to place their business with Dan-Air and only then placed its contracts, fitting in with whenever aircraft and crews were available. This meant that a lot of Intasun's business involved mid-week and night flying. This, in turn, was a win-win for both operator and airline. It enabled Intasun to charter aircraft at substantially lower rates than its competitors, who had to pay a premium for chartering planes at weekend peak times and it permitted Dan-Air to increase its fleet's utilisation, thereby boosting the company's overall profitability. However, the high fuel consumption of Dan-Air's "mix'n match" fleet – especially the Comets, which at that time made up the bulk of its charter fleet – against the backdrop of steeply rising jet fuel prices in the aftermath of the 1973 oil crisis made it more and more difficult to offer Intasun the rates at which it was prepared to contract its business to Dan-Air.