Now, I didn't expect my single little failed fraud attempt to merit individual investigation. I had hoped that they would put it on file, and use it as supporting evidence for conspiracy in a larger case later on, but no-one tracks these things.
Oh, but they do. I did a similar thing, regarding about a scam letter, physical mail, I received several years ago. I got the normal "Thanks for reporting" response and thought nothing of it, as you did. About 6 months later I get an email from the US Federal Crime Victim Notification Service telling me that an investigation had been opened into the company I reported.
I've been getting regular updates through this system for about 3 years now up to and including verdict & sentencing. There were 6 or 8 people who were charged, a couple plead guilty to lesser charges, one was found guilty of some fairly serious charges and the ring leader was found guilty of many counts of fraud and related charges and sentenced to, if I remember correctly, 17 years in federal prison.
I was completely surprised by it because, like you, I had never seen anything come of the various things I have reported over the years. But, apparently, they do pay attention if they get enough complaints.