Our favourite definition comes from Andreas Kaplan and Michael Haenlein definition: "a group of Internet-based applications ... which allows the creation and exchange of user-generated content."
One in three people spend more than 3 hours per week on the mobile internet and many use it for social media. Nearly 70% of the UK with a mobile phone spend more than nine hours per week online according to Skopos, with the vast majority using it to access social networks. Facebook in the UK now has 60% of its users coming from mobile devices.
Social media is something you now need to design your services to run on.
Social media lets you to connect with customers and potential customers. You can use social media to target customers with certain definable demographics as well as use the 'sharing' principle to extend your reach across your customers' social network.