Agreed. In general: 1) Successful people tend to be found in selective environments. A website that lets anyone in will by definition be filled with junk, bore

Agreed. In general: 1) Successful people tend to be found in selective environments. A website that lets anyone in will by definition be filled with junk, bored people, teens, and time-wasters. Since 'successful people' know this, it's a self-fulfilling prophecy (they know their peers aren't there). 2) Most professional peer connections are still offline. Want to know what your peers think about a recent paper? If you're established in your field you'll know them on a first-name basis and will just call them. Twitter is the only exeption to both these rules, miraculously, though only to a degree.