Oh goodness, yes! I would be completely stuck tracing a gg grandmother's family, were it not for a flowery Victorian newspaper marriage announcement mentioning her father's address and a brother's address, since her father was living in Inverness and she (for completely unknown reasons) in Lancashire! I have no other way of tying her definitively to her father.
Found a lot of information on her father: properties he was advertising for sale/rent at various points; a farming competition that he features in. Found a lot that has added extra colour to his life in Inverness and helped with what he was doing when.
As others have mentioned, local newspapers can also help you build up a good picture of what an area was like at a particular period.
In relation to other family members, I have a burglary, an automobile accident, obituaries, military announcements, bankruptcy announcements, advertisements with information about the nature of businesses carried out at addresses of interest -- tons of stuff, in fact.
I'm certainly one of the lucky ones!
CELTICANNIE