Posts made on Facebook at 3pm on a Wednesday are the most likely to generate reactions

"A new report from Vitrue has analyzed data on Facebook to determine when is the best time of day to make a post. After studying more than 1.6 million posts, 7.56 million comments and 1,500 brand streams, it boils down to this: Wednesday at 3PM ET.
It is, Vitrue, said the consistently busiest period. In general, it found that  the best usage period were 11 AM, 3 PM and 8 PM ET."
Source:  Research from Vitrue, reported by MarketingVox, 28th October 2010