OH THAT... but that is just happening IN your client, in my case Firefox.
No. That's not quite what is happening. Your client (Firefox) requests a bunch of mails residing on Gmail's server somewhere. The server then scans the mails for keywords, finds the relevant ads in their database and then returns a html page with emails and ads combined.
When I open a mail (or write a mail) Indeed, gmail will display ads on the side bar and one small ad above the mail interface. But that is merely the page sending out a request to the google ad server thats tagged their ads with relevant keywords...
Google has to have access to the full text of your email to be able to scan for keywords ...
That a whole other thing than Google "scanning you mails" as they are sent...
In what way?
Ian