Twitter who are planning to start charging brands for commercial marketing activities, has triggered a debate over how the service can distinguish between individuals and brand users.

The social network site has gained popularity in the UK thanks to celebrity users such as Stephen Fry and Jonathan Ross.

Robin Grant, managing director of agency We Are Social, said: ‘The challenge Twitter will face is that there’s such a grey line between personal and commercial use. If I spend a lot of my time on Twitter talking about business-related stuff, where does that leave me?’

Cheeze director, Jamie Riddell joined in saying rather than charging brands, Twitter could market its search tool and introduce revenue from pay per click.

Others suggest that, like Facebook, Twitter could sell targeted ads within the stream.

But Brendan Mitchell argues that adding ‘an extra layer of services worth paying for is a better approach, as long as it doesn’t alienate or lessen the initial free service’.

George Nimeh, managing director of Iris Digital, insists that the real value is not in charging companies for display ads. ‘Access to customer information for marketing, on the other hand, is certain to have tremendous appeal.’

Where do you stand on this debate, are Twitter justified in charging brands that are marketing on the site?