Larry is right about the Google ads,
I just went to the BCT page and read the new podcasts and noticed a new one, Popping Popcorn On The Stove.
Then I went up to the ads and found,
Get a Free Electric Popcorn Popper Guaranteed Free Limited Time Offer!
That's one smart program that probably searches the page for new words and then compares them with a list of key words in advertisements.