I'm currently with them on a one year free membership offer they gave me which runs out in October. They gave me lots of vinyl signs which I've put some on my van. They've also put an advert of my business in their booklet which is delivered to every house within a 5 mile radius of where I live 3 times a year. There is only one other window cleaner advertising in it!
The most important thing though is all the business that I've got through it. If I had paid for the service then I reckon I probably wouldn't have covered cost but I've still managed to get over £600 worth of new work through it!