Source 1 million, 5 million, 10 million…? If you guessed 10 million, you weren’t even half right. According to new data from Pingdom, Twitter users are averaging 27.3 million tweets per day with an annual run rate of 10 billion tweets. Just last month, Caroline McCarthy of CNET reported that the 5 billionth tweet posted. Pingdom’s report highlights the pattern of tweets, which appear to spike during waking hours in the U.S. However, it’s important to note here that Comscore…