The campaign, which runs until March 2008, was devised by marketing communications agency Elvis. It invites Cadbury Dairy Milk buyers to text the last four digits from the barcode on product wrappers.
The winners, who will be chosen at random by a draw engine provided by mobile marketing company Sponge, will be contacted within 24 hours by Cadbury to be informed of what prize they have won.
The prizes for the text campaign include digital album downloads, five-star holidays to Las Vegas, salsa lessons in Havana and designer clothing to wear to a film premiere.