Sprout keeps growing.

John Pelz at Crain’s is reporting that Sprout Social has raised another $8 million from VCs Lightbank and New Enterprise Associates.

The one-stop-shop for social media monitoring and management, Sprout Social is looking to expand internationally and will use this latest round to launch into more markets and potentially establish a European headquarters.

Having gone live in ’09, the company is one of the fastest growing startups in the city – they doubled their workforce in December, adding 100 new employees – and this latest influx of cash will help Sprout Social maintain that reputation.

NEA and Lightbank invested $10 million in 2011, so the company gets another round from its primary investors, keeping the VC influence nice and focused.

The company will also use the round to develop new features and products as well as grow its sales and marketing team.

Justyn Howard and Aaron Rankin, CEO and CTO respectively, will be speaking at Techweek today about managing social media in the 21st century. With this latest round, you can expect Sprout Social to be a significant factor in this dialogue for year’s to come.