DocuSign, which allows businesses of all kinds to sign documents electronically, is looking to raise $100 million at a valuation that could top $1.5 billion, reports The Wall Street Journal, citing three people familiar with the deal. The company was started in Seattle by entrepreneur Tom Gonser, a former McCaw Cellular employee who now serves as chief strategy officer. It has operations split between Seattle and San Francisco, the latter being where CEO Keith Krach is based.