European mobile operators are still contemplating giving mobile services away for free to consumers. The catch? Consumers have to agree to receive advertising on their mobile phone. UK mobile virtual network operator (MVNO) Blyk recently launched a new variation of this concept with a business model that's based on ad-funded services, including voice and SMS messaging. The Blyk model will face challenges in getting consumers to accept advertising on their mobiles as well as in signing customers up online and keeping them loyal. Blyk will also have a tough time convincing marketers to advertise with it until the MVNO can show significant reach; precise targeting won't make sense until then.