The company has 'plugged into' the international market. [=the company has become connected to the international market; the company has begun to do business in the international market]
His friends are 'plugged into' the city's music scene. [=his friends are actively involved in the city's music scene]
The computer program will take data from these sources and automatically 'plug' it 'into' the equation.
(..) - Good to see you. - Are you a big fan of Slater? I have enjoyed it. It was just beautiful. The National Enquirer. Do not talk to them. Do not plug the restaurants. I hate that. It is so tacky. - Why go to the movies? - To get help. Benedict can do anything. But we know who he is. (..)1993 Last Action Hero