Snapchat is poised to pull ahead of Twitter and Pinterest in the US for the first time, with fresh research forecasting that the messaging app will grow its user base by double digits to reach almost one in five Americans. Snapchat’s stateside user base will jump by 27.2 per cent to 58.6 million, outpacing Twitter which will have 56.8 million users in the US this year according to eMarketer. Forgoing figures supplied by social networks, which often disclose daily or active us