How do I know that a Penis enlarger will......

This morning, I had rather a nasty shock. I arrived at the Club at 10am and opened my emails in order to collate the party and banquet invitations as usual.
There was one email that was in the "junk" file, that caught my eye.
The subject title was "Tiberius Erectus" and, as he was an old school chum of mine (I thought he had died years ago), I was compelled to open it.
It was a ruse.....apparently it was from a firm that make ALL sorts of naughty things, many of them electrical, and they were offering to increase the size of my manhood at a very reasonable price.

Being concerned about privacy and computer security, I opened up the other junk mail, and lo and behold....apart from one that was offering substandard pay to illegal immigrants who were prepared to work as a farmhand/Gibbon pacifier, they were all offering to increase the size of Percy, either by a herbal remedy, or something that involved suction.

Now, I have two questions:-
1. How did they know about my problem?
and 2. Has anyone tried one, and do they work?

Ellpus.