Back in the days of EA, we used the player names on battlemetrics to track known exploiters to find out if they were on the server. We didnt have the in game server lists so we used battlemetrics to get the player names, then cross referenced it with the steam list in game. It allowed us to know when exploiters from a certain country were online, and allowed us to adapt our playstyle to match it - going from farming to fighting mode. When we seen them online, our farmers were pulled into the bases and our fighters went out looking for them. Keep in mind this was during a time when those types of people only built under the mesh. It became all eyes on deck to find them.
Thats what we used them for, others I cant speak for but I imagine it was similar reasons.