Earlier this year MasterCard gave notice that from this summer it plans to start charging a fee on 'staged' digital wallets such as PayPal, Google Wallet and Square.

According to a recent note from Nomura Equity Research analysts Bill Carcache and Brian Nowak, obtained by Reuters, these staged wallets share less information with card networks, creating customer service problems.

While the fee may be designed to extract more customer information from wallet providers, the Nomura note also suggests that MasterCard is reacting to an increasingly threatening rival in PayPal, which is aggressively moving beyond e-commerce to the high street.

Say Carcache and Nowak: "Payment networks are taking the gloves off. The incumbents will do everything in their power to prevent PayPal from riding on their rails without extracting a toll."

Continue the pair: "Now that PayPal has started moving to the physical point of sale...competitive intensity levels are rising as PayPal encroaches deeper into what has traditionally been the incumbents' turf."

Although the fee is unlikely to cost eBay a significant amount, the analysts suggest it is just one part of a broader trend worrying investors and contributing to a four per cent dip in its share price so far this year.

EBay hit as "gloves come off" over PayPal digital wallet fee - Reuters