The theme is 'celebrating 100 years of happiness' and activity will centre on Cadbury Dairy Milk 'sharing moments of happiness' with the nation throughout the year. The confectionery brand is boosting its marketing spend by £5 million to capitalise on the celebrations.
The site (www.cadburydairymilk.co.uk) includes a range of interactive features such as a weekly competition to win high-value prizes and ecards.
Users can sign up for 'happy thoughts' to be sent by email and find out facts about the brand. A heritage section will include the history of Cadbury Dairy Milk.
An interactive element allows users to vote for the contents of a physical time capsule, which will be buried at the end of the year, and they can download games and screensavers.
The site will be pushed though on-pack promos, PR and online, supported by below-the-line agency Elvis. Details of the web marketing push had not been finalised at the time of writing, but the brand will build on a smaller advertising test, which was carried out in September.
Agency Big Group developed the new site. It also redesigned Cadbury.co.uk, which launched last January.
Activity supporting the Dairy Milk range also aims to boost its other chocolate brands, such as Roses and Flake.
Frances Dovey, Cadbury's UK internet manager, said: "2005 is set to be the biggest 12 months in Cadbury Dairy Milk's 100-year history and we aim to touch the lives of everyone in the country with our celebrations."