Cadbury brought back the Wispa bar in 2007 after a Facebook campaign

The Wispa, an aerated chocolate bar launched in 1981, vanished from UK shelves in 2003 amid declining sales and was replaced by Dairy Milk Bubbles. Fans kept asking for it back, and by 2007 online petitions and social networking campaigns were impossible for Cadbury to ignore.

In August 2007 Cadbury agreed to relaunch the Wispa for a limited period, with 23 million bars available from October. Spokesman Tony Bilsborough said consumer passion had swayed the company, and that it was the first time the internet played such an intrinsic role in the return of a Cadbury brand.

Almost 14,000 members of a Facebook group helped carry the campaign, and BBC coverage in December 2007 showed how the revived bar rode social-media nostalgia back onto shelves. Cadbury said that if sales stayed high, the Wispa could remain a permanent product.

Cadbury relaunched 23 million Wispa bars in October 2007 after petitions and a Facebook group of 14,000, keeping the bar when sales held.

A visible Facebook group of ~14,000 members proved demand

Online petitions gave the campaign an organized form

A limited run of 23M bars capped the downside

The bar's 1980s cultural status made nostalgia easy to sell

Nostalgia demand can be measured before production: fan petitions and groups forecast sales, and a limited run tests demand without committing the brand.

The Wispa's limited relaunch sold well enough that the bar stayed on UK shelves and eventually returned as a permanent line. The episode became a landmark of early social-media marketing: it showed a company listening to fan demand online and converting nostalgia into a low-risk, limited production run.