Rabbitmq -- probably the most popular messaging system
Riak -- distributed, fault tolerant database
WhatsApp -- managed to route billions of messages a day with only a handful of engineers and servers.
Ericsson -- pretty much got the market for cell base nodes cornered. Chances are about 50% if you use internet on your smartphone, that Erlang will be involved.
Some firms on Wall Street use Erlang -- remember Serge Aleynikov case, he is an Erlang programmer.
Ejabberd -- a very popular XMPP server
CouchDB/Cloudant(IBM) -- another database and database-as-a-service company use Erlang.
So I would still say the original statement holds. By success might mean the amount of work being done not amount of people writing code. Think about WhatsApp. It was only 10-20 engineers that worked on the back-end yet think about the massive amounts of data they were able to handle.
His erlexec thing is quite useful: https://github.com/saleyn/erlexec - I started contributing to it myself before I realized who he was.