The story
The company was founded in 2010 by Stuart Wall and John Buchanan out of Harvard Business School. It has raised $30M in venture funding from Georgian Partners, Google Ventures, Spark Capital, OpenView Venture Partners, Scout Ventures and a group of angel investors including Jason Calacanis, Thomas Lehrman, and Jack Herrick.
From Wikipedia’s article on Signpost (company), shared under CC BY-SA 4.0.6