US dollars in Jamaica

As you can see on this very detailed report on Tripadvisor, it depends where you are and what you are trying to pay for. This by the way goes for any other place that is highly frequented by one specific nationality, such as Macau and HKG for Chinese currency, Switzerland for Euro etc:

Places frequented by tourists will accept USD. There is a chance that you will get change given in local currency. Exchange rates might be not as favorable as at a bank. So you pack of gum depends on the question if it's at a kiosk next to the place where Bob Marley was born? Likely yes. If it's from the street vendor in a place where they only see a foreigner once a quarter? Likely not. Unless, of course, you are willing to pay 15USD for that pack of gum, of course.