CBS has finally broken the silence about how many subscribers its All Access OTT video service has, claiming 2.5 million sign ups and projecting progressive uptake in the region of 5.5 million new subscribers over the next four years. Subscriber figures for HBO Now, CBS All Access and Showtime OTT (which CBS also owns) are more difficult to calculate compared to other major subscription services, partly due to secrecy and partly down to sign ups coming in peaks and troughs in sync with releases of popular titles attracting mass subscriber influxes, as is the case with HBO’s Game of Thrones and CBS’ Star Trek series. The wait for confirmation has finally arrived and while the current figure was in line…