eFax – does it get money from spammers?

I’ve had a free eFax account for some time, but on several occasions my account has been suspended by eFax as I’ve been told I have received too many faxes for the free service.
The interesting thing is, that I have not given my fax number out to anyone. The faxes all came from spammers!

Today, in an online discussion about business communication, eFax came up and someone (who I know and trust) wrote:
A note about free eFax: according to an eFax employee, you should expect to get a lot of SPAM with the free account because that’s how they support the free accounts. I’ve had the paid account for about a year and haven’t received ANY spam.
I talked to an eFax employee and they said that sometimes spammers just randomly dial and get fax numbers.
I bet the truth lies somewhere in the middle.