What does well-placed sources mean in the following text?

NBC executives expect Katie Couric to leave the "Today" show and acceptan offer from CBS to become the first woman to anchor a network eveningnewscast on her own, with an announcement of her departure likely asearly as this week, according to well-placed sources at both networksand others familiar with the negotiations.
Sources - people who are a source of information

Well-placed - suggests that they are in a position to know what they are talking about. A cleaner could be a source - but would they really have accurate information? No.
Thank you, Nona.