Swallow explained: they had a low-key attitude to the region and had just wanted to get a foot in the door. (BNC)
His parting advice to those interested in taking the challenge was: keep an ear to the ground, your back to the wheel and get your foot in the door. (BNC)
I'm not saying it happened on this occasion, but it is not unknown for a private company to take a loss on government contracts to get a foot in the door. (BNC)