I heared this on last years YAPC::EU and I read about this from the report chromatic wrote about YAPC::NA.
This is great. This means Perl conferences attract many new people.
This also means that many people don't come to a second Perl conference.
(I don't know about YAPC::NA but AFAIK YAPC::EU did not grow in the past few years, if anything it was shrinking in size.)
So why do so many people stop coming to Perl conferences right after they have been to one?
As most business owners can tell you, the best are the returning customers.
Why are the Perl conferences not turning newcommers into returning visitors?