Summarize this blog post with:
A new report just released from Nielsen outlines some very impressive growth for both Facebook and Twitter.
In March 2010, Facebook reported over 117 million unique US users–a 69% year-over-year growth from March 2009.
Twitter reported 20.1 million unique US users in March 2010–representing 45% year-over-year growth from March 2009.
For the full report visit the NielsenWire.
