yes, i did it and yes i got bookings from them.
not a lot .. but some. and i also got inquiries not invoving the hot deal.
mostly i did it so it got my name in the emailing ... but i didn't do it every week ... i would look at my upcoming bookings and decide. i think you had to decide the week before each mailing.
i had another email address (my personal one) on the mailing list so i could check. yes, the mailings were reliable.
i also participated in my state tourism site's specials and my listing on bbonline always had a couple specials so i'd turn up in those searches.
it didn't cost me any more to participate, i am sure i was not at any high level .... it seemed i was always running some kind of special ... when you are in a market where you have to draw people in, you use the tools available. and i was always working to bring people in. there were very few times when i would be completely booked. and my overhead in that big old building was crushing.
i would say, if you are going to run a special that fits their guidelines, and you have a listing with them, get your special in the hot deals for the upcoming timeframe. use the tools that are available.