Success stories of PostgreSQL implementations in different companies

Hi, this question isn't technical, but is very important for me to know.
Currently, here in El Salvador our company brings PostgreSQL support, but
Oracle and SQL Server are more popular here.

Even with that, some clients are being encouraged to change to PostgreSQL
to lower their companies costs in technologies, but very often they ask if
there are success stories of PostgreSQL implementations in companies in our
region or around the world, success stories (if is possible) with some
information like number of concurrent users, some hardware specs or storage
size.

I think that in my country is more common to hear success stories like that
about other databases like Oracle because is more expanded here, but i
would like if there's a place or if you can share with me some real
experiences or success stories that you ever heard of successful
implementations of PostgreSQL in companies to talk with people when they
ask that kind of things.

Regards.

***************************
Oscar Calderon
Analista de Sistemas
Soluciones Aplicativas S.A. de C.V.
www.solucionesaplicativas.com
Cel. (503) 7741 7850