Hi Guys
Couple of things spring to mind.
They have obviously worked hard and promoted their site heavily.
What is most important is being top for the key words most will search for and that is carpet cleaning, cleaners etc for your areas, in my case Essex. These rankings do not change very often and because it is difficult to achieve, then it is worth having .
Wouldn't be much point in being top for a day and then relegated by the new kid on the block.
As for the NCCA i have long thought that it's only marketing tool is it's excellent rankings, it will need to work hard to protect this.
Cheers
Doug