The $7 billion 2012 forecast was made by eBay CEO John Donahoe at the CES technology show in Las Vegas.

it comes after a breakthrough year for mobile shopping as PayPal hit $4 billion in mobile payment volume, a huge increase on the firm's original 2011 prediction of $1.5 billion and the $750 million in mobile payments captured in 2010.

Donahoe says the firm currently has more than 17 million PayPal customers regularly making a purchase through their mobile phone, up from the eight million reported in June.

Mobile shopping apps and tablets are expected to play a major role in driving adoption, he says.

Recent IBM Benchmark data indicates that 75% of shoppers this holiday season made purchases on their tablets, with the iPad driving the bulk of these transactions.