I bought this little over a year to switch off my hi-fi kit when its standby. It started playing up after about six months. Even after changing the batteries, it was pretty unreliable and completely died after less than a year. Considering it cost £35 from Costco at the time I bought it, the cost hasn't covered the additional electricity used if everything plugged in was left in standby, or the energy cost of producing it.
Its a cracking product when its working but it needs to last at least 5 years. I wouldn't buy this unless it comes with an unconditional warranty for that time.