A year ago, having just bought Twitter, Elon Musk walked into its HQ carrying a sink. "Let that sink in" he quipped - then fired a large swathe of staff. It was the first flavour of what has been a 12-month whirlwind of erratic change - not least the renaming of the company to X. In some ways, X has been remarkably resilient. Despite rivals old and new circling, it survives. But, with advertisers wary and user metrics shaky, what's next for X? Please subscribe here: http://bit.ly/1rbfUog #Twitter #ElonMusk #BBCNews