The challenges of payment transactions in electronic commerce were initially underestimated, as is now clear in the light of advances in e-commerce, traditional business models are increasingly coming up against their limits. Secure, user-friendly and low-priced innovative payment solutions are urgently required to boost internationally oriented e-commerce. Value-creating market players - from payment system providers, service providers, network operators and producers of terminals to financial institutions - pin great hopes on the rapid progress with new payment systems. In the medium term, mobile phone-based payment systems will be an even more valuable channel for e-commerce than internet-based systems. Nevertheless, in the longer term, upgraded traditional solutions (credit cards and debit cards (especially in Germany) and smart-card-based electronic wallets) are likely to push aside the innovative systems.