San Francisco -- DocuSign, the San Francisco-based developer of a cloud-based network for sending, signing and tracking documents, said on Tuesday it has landed a new investment from Google Ventures to close its fourth round of funding at $55.7 million. The company initially had closed the round last month at $47.5 million, led by Kleiner Perkins Caufield & Byers. DocuSign said it will use the funds to accelerate growth of its network through increased customer-focused research and development, deeper vertical industry focus and faster international expansion. The company said 60,000 new users are joining its DocuSign Global Network each day. The network now includes 20 million users who have electronically signed more than 150 million documents in 188 countries.