Ciao enables members to write reviews and earn from them - in this respect it is quite similar to how dooyoo works, but in my opinion in nowhere near as good.

The website:
Personally I've found ciao's website a little on the confusing side - navigation is clumsy and even the FAQ's don't always properly answer the questions posed. The design is poor and the account section which details what you have earnt is very unclear, I still can't make head or tail of it.

How does it work?
You don't get paid to write reviews, instead you get paid for the rating's your review receives. Each review rating can be worth between 0.5p and 2p. When writing a review on a product you should check if there is a £ symbol next to the product name - if not you won't receive any money from rating's either.
When being rated by other members I have found that people tend to give harsher rating's on ciao than here on dooyoo - my reviews on here that have been rated as 'very useful' are often only rated as 'helpful' on caio (equivalent of useful).
Each month ciao rewards the writers of the best reviews with their premium fund. This fund totals £2000 and is spread out amongst the best reviews - personally I have received £2 of this but still can't work out what review I actually got it for.
When you reach £5 in your account you can request a payout which is paid directly into your bank account. They process payments once a month so it may take sometime to receive your money.

What's it like for earnings?
Let's face it, even thought most of us enjoy writing reviews, we are also in it for the money. I've already explained above what you do and don't get paid for, but how does this translate into real world terms? I've been a member of ciao since October 1st 2009 - from then until now (7th January 2010) in that time I have posted a total of 27 reviews and I have accumulated £6.36 in earnings - £2 of this coming from the premium fund.
I imagine if you spent all day, most day's on ciao writing reviews then you could probably earn a decent amount of money from it but it still wouldn't work out to anywhere near minimum wage.

Is it worth bothering with?
If you are already writing reviews for a site such as dooyoo then I would say it's worth being a member of ciao too - you are allowed to place the same reviews on both sites (just make a note that you have done so in your review) as this way you can earn a small amount for just a few seconds effort. However if you are thinking of using ciao as your sole source of money making from reviews then I'd think again.