Since at least 2007. I had originally gotten it to try the AMEX traveller's check deal, but it didn't work out. Did enough spend to get to the 20K threshold and stuffed the miles away (in late June this year, as I recall).

It was also good for recommendation bonuses, which gave me another 20K (4 boni) and then their card went into miles with the BA bonus.

The same folks have also gotten their new cards, so it's been a pretty good ride with AMEX so far.