Recently I wrote two blog entries that might be of interest to you.
The first one is a call for people to help with the booth at LinuxTag Berlin:
In the second one I added some numbers I apparently missed from previous
reports in FOSDEM and CeBIT
In short my estimate is that on FOSDEM we talked to 3-400 people while on
CeBIT we talked to about 1,000 people.
On LinuxTag I expect about 6-800 visitors to our booth.
Compare that to the number of people on the regular Perl events
such as the GPW with 130 visitors or YAPC::EU with 300 visitors.