I smell sarcasm in your comment. But the point is that yes, I expect Google/Gmail to understand that when I'm marking an email as "Spam" or "Not Spam" by clicking the buttons they put there, similar emails should be flagged (or not) accordingly next time one comes in. If clicking these buttons doesn't do anything, they should just get rid of them.
Sure, I could use epochwolf's suggestion with filters, but filters are for granular sorting and personal preferences: adding labels, skipping inbox, forwarding, etc. that would be pretty much impossible to guess for a "machine". As far as I'm concerned, clicking "Not Spam" should be very similar to creating a filter that says "every email that look like this (same address, same kind of content, etc.), do NOT mark it as spam". If this is not what's happening, these buttons are just useless.
I do want google to take all of the data they keep on my searches and all the little scribbled notes their furtive servers make on my whereabouts as I stroll around the web and put it to use to make my experience better.
Did google show me an ad at http://troutpeeler.com? [1] Did an email come to me from do_not_reply@troutpeeler.com 5 minutes later about an order from me? That isn't spam! And now they know I'm interested in at least one sort of fish peeler. Take that into consideration when a commercial mail for fried fish skin enthusiasts shows up at my inbox.
[1] This is meant to be a fictitious instance of a web site and a product. Heaven knows I'm rubbish at making up unused names, so there probably is a Trout Peeler website somewhere and a group of peel that make fried fish skins. I don't want to hear about it. Ick.
[2] I wonder how many people with browser extensions have to click on http://troutpeeler.com to trick a name squatting robot into reserving the name.
Sure, I could use epochwolf's suggestion with filters, but filters are for granular sorting and personal preferences: adding labels, skipping inbox, forwarding, etc. that would be pretty much impossible to guess for a "machine". As far as I'm concerned, clicking "Not Spam" should be very similar to creating a filter that says "every email that look like this (same address, same kind of content, etc.), do NOT mark it as spam". If this is not what's happening, these buttons are just useless.