When contacting buyers/tyre kickers I always provide my mobile number via PM, maybe this should become mandatory?

Folks could always provide dodgy details, but they'd get weeded out pretty quick. It's always easier to contact someone then rather than have the seller eventually post in their thread that their computer died, they had an urgent family matter or whatever the excuse may be.

Communication is key, non response can be construed as an admission of guilt (by some, me included), if you aren't prepared to provide contact info up front maybe you aren't fair dinkum?