Two years ago there was an amazing cash back deal... $15 off each booking
I was just about to start my travels to Philippines, Malaysia etc. Considering the low prices there it made huge difference and I book everything through booking.com - even though agoda, hotels etc were cheaper.
It took 90 days after the stay to get credited.
Long story short - they changed the T&C with effective date "3 months ago" and I got just about $60 while paid significantly more in compare with using other sites :/