Big influence:  If Mark Zuckerberg was planning a run at the next US presidential campaign, he would have a powerful strategic tool in Facebook. Photograph: Brian Snyder/Reuters

Digital advertising is now proficient at targeting individual consumers with tailored messages for specific products. If you want to sell skin cream t(...)

Of all the parties in Northern Ireland, Sinn Féin has by farthe biggest income. It is also the biggest spender, notwithstanding that in terms of vote(...)