Just to make as many people as possible aware. Some of the big holiday rental sites (such as Owners Direct and Homeaway - probably others too) are soon to start adding an additional 6% onto a booking. They call it a Traveller Service Fee. This is in top of the commission which they already charge most owners.
It is always a good idea to google the name of the property and see whether the owner has a truly "direct" website because the price you pay will almost certainly be cheaper. I have a 2 bedroom cottage in Devon and it would be around £100 per week cheaper to come via my own website.