I think it goes in swings, I have had 3 quotes off the web site this month, some months are quiet and some I will get two or three a week. Click fraud is exactly why I do not use adwords and google does have some systems in place to monitor it. I use stat counter, and it gives me the IP address of the person that clicks onto my site, what pages they visit and how long they were on each page. I can pop the IP address into arin who is, and if they have their own server, I can find out who it was that came on to the site. That has been useful as I have been able to contact a few companies that were looking for a cleaner but did not fill out my information request form. I landed one contract for 1100 per month that way. I seen who they were and then cold called them and got the appointment and 3 months later got the contract.
I think the next couple of weeks will be pretty slow though, not to bothered either, would like a little time off, but I will not pass up the chance on a good contract either if someone contacts me.
Another thing that stat counter will do is tell you the refering link. I have seen a few from this site where they click on my link that I have here and then go to my site and check it out. But it shows if they come from a directory and I even know when google bot ges and crawls my site.
Cheeres
Gilbert