Its always 10% off online
Ive used them for years, never had to claim fortunatly, but their pricing is excellent especially for the service they claim to offer. Its even better when you take into account you can spread the cost over 12 months by direct debit (its NOT NOT NOT a credit agreement unlike most shop warranties and is cancellable at any time, see below for refund info), which means it works out at like a few pounds a month on average.
My dad has claimed with them once or twice for faults (once was accidental damage i "think") and never had any bad experiences and always recommended them, so I go by his word.
Got everythin electrical insured with them, far better then the crap you get with these "extended warranties" that stores sell, and cheaper too.
One other thing is, if you decide to end the cover during the manufacturers warranty period (say you sell the item on and dont transfer the cover), provided you have not claimed, they will refund the full amount back to you that you have already paid. I had a TV that I had insured, the direct debit got cancelled by accident, I didnt take heed of the letters they sent for some bizarre reason, then a couple of weeks later a refund appeared in my account for summit like £66 (I was only 1 month away from paying the full thing - gutted lol). Phoned them up and they re-activated it for me anyway and took the payment by card. But it goes to prove that they actually do refund if you cancel (even if you do so inadvertantly like I did lol).
My Technics Hifi was £599 a few years back, when I insured 2 months later, if I had gone through DomGen direct, it would have only cost £47.00 for 4 years cover against breakdown and accidential damage (I went through Panasonic in the end - they actually use DomGen, but it meant I could take it direct to any Panasonic shop or agent and get it fixed without having to arrange a repair with DomGen first - the insurance still came from DomGen though).
Overall, id recommend them