Job postings on online business marketplace PeoplePerHour.com for ’Twitter consultants’ have risen by more than 300% this year as more firms see the value of integrating social media like Twitter, Facebook and YouTube into marketing plans. “We’re seeing increasing demand for social media experts to oversee the Twitter feeds and Facebook pages of a very wide variety of companies,” said PeoplePer Hour.com founder Xenios Thrasyvoulou. “We’re six to 12 months behind US companies,” observed Tony Wood, a freelance social media consultant from Norwich. “In the US, around 90% of the top companies are really serious about social media and have invested in the infrastructure to make things happen.