First let’s have a look at a game from this day: 28 July. A pre-season friendly with a nice array of goals
Three dates for 28 July, all connected with transfers that were financially incredibly good value for Arsenal.
On 28 July 2000 Marc Overmars and Manu Petit signed for Barcelona. At €40.6 million Overmars was the most expensive Dutch player of all time but injuries inhibited his style and he rarely showed the quality that he had delivered at Arsenal. Including wages he cost Barcelona around £4,000,000 a game.
On 28 July 2002 Arsenal signed Gilberto Silva for just £4.5m. The low fee came because Atlético Mineiro had not paid their players, were banned from transfer deals, and there were problems getting the work permit despite the fact he went on to captain Brazil.
And finally on 28 July 2009: Kolo Toure sold to Man City for £14m thus making Arsenal a profit of £13,850,000. He played 82 games for City before being transferred on to Liverpool on a free – thus costing Man City £170,731 per game. There is a video of Kolo describing his transfer to Arsenal on the Arsenal History Society website
Of course these are not the only profitable transfers Arsenal have made across the year, but this is probably the most profitable transfer day for the club.