This guy shows you conclusive evidence that Google is always listening to your conversations.

The video is slightly NSFW for his exclamation when it actually works.

This guy wanted to prove that Google always listens to what you're talking about in order to show you ads that are directed more for you.

He says in the video that he really didn't think it would work.

So, first, he writes down what the subject was going to be, which was "Dog Toys." He shows the sign so as not to let Google know. He uses Fark.com to open up several different websites, and then checks the ads. None of them have dog toys as advertisements. He closes his internet browser.

THEN, he starts talking about dog toys out loud like he is having a conversation with a friend. He mentions dog toys several times. Even goes to specifics to say red or black Kongs.

He then goes back to Fark, and reopens some of the same sites, and some new ones as well. And the very first one...BAM! Dog toys.

After a few websites, there is even specifically black and red Kongs in an advertisement.

Time to get off the internet.