Moto GP in Thailand is highly popular and shown on Thai TV due to Thai rider somkiat chantra who will be in Moto GP next season so it will increase the popularity more.
The tickets for the weekend in main grandstand seats sell out usually in 2-3 minutes as you can see the whole track from there , the other stands around the track probably sell around 70-85% and are usually cheaper and associated with certain riders in Moto GP.
It's actually really well organised and a good weekend out for all ages of people .
The riders and commentators like the track also as it provides close racing and tight finishes due to track layout.