Could be the time of day, day of week. It could also be the more recent movements of stock prices setting a context where this is more interesting to people (a number of articles on Facebook prices in just the last few days). Who knows?

More than likely. Still does highlight that its not just the news but also when you and as you say many prevailing aspects come into play. Like comedy timming is everything and that does seem to carry for many other aspects of life with regards to interaction. Fascinating though non the less.