I got a flyer in the mail today showing an offer for a free Sonos Play One Smart Speaker with any purchase of $799 or more at The Mattress Firm.
This isn't so much of a "deal" as it is a promotion, but if you're in the market for a bed, might be a nice perk. This might also be a local deal only (I'm not sure... I live in the suburbs of Atlanta) so YMMV.
EDIT: So, it appears to be all stores since it's on the website.