Wow, you sure it was them? You didn't divulge anything to them, did you? Honestly, I'd be a little startled if Google called me out of the blue, that goes for Yahoo too. (unless I told them beforehand to contact me via telephone) Maybe Yahoo on the phone would be more productive than email communication. Kudos to them, and I've made special note Not to steal OP thunder, but I hope you are NOT going to let them slide on that!
Got another call from them today. My rep spent half an hour on the phone showing me how use the ad writing tools! Again, Much appreciated !!