With all the special offers going on in the supermarkets I wouldn't have thought there was room for a site dedicated to discounting the big brands but apparently there is: yourfavouritewines.com
The proposition is simple - they offer discounts on the best known wine names in the high street. Nothing wrong with that - we all like a bargain - but do bear in mind that the prices of many of these wines are pitched for discounting which can make the price reductions not quite as compelling as they seem.
They do have the advantage of having a former supermarket wine buyer Angela Mount on board though who used to head up the wine department at Somerfield and whose tastebuds were once famously insured for £10 million pounds. (A brilliant piece of PR!)
I guess it would be most useful - like any mail order service - to people who live miles from a supermarket or who don't have a car. All I'd suggest is that you compare their prices with other sites such as mySupermarketwine and wine-searcher.com or even a supermarket online wine site like TescoWine to make sure you are actually getting the best price.
Also keep an eye on the vintages. Some of them, like Louis Latour's 2007 Ardeche Chardonnay (reduced to £7.16) are clearly bin-ends. That's quite elderly for an inexpensive - or relatively inexpensive - white.