Consumers signing up for a Vodafone dongle on an 18-month contract can avoid paying a penny for the first three months of their deal.

The mobile broadband provider offers three options for customers willing to commit to a long-term deal - its Starter, Premium and Ultimate packages.

With Vodafone Starter, which carries a monthly price of £15, subscribers gain a 3GB usage allowance, basic PC protection and 2GB of PC backup.

For those likely to spend more time on the internet, Vodafone Premium offers 4GB of data for £20 per month, while Ultimate costs £25 for a 5GB usage allowance.

The two more expensive dongle deals offer premium PC protection and a 20GB backup allowance.

As well as receiving three months free access to the web when signing up, subscribers receive a complementary dongle – eliminating start-up costs altogether.

Vodafone's USB modems are suitable for use with the Microsoft Windows XP, Vista, Windows 7 and Mac 10.6 operating systems.