When going through your Twitter feed you may have noticed that some tweets begin with a period, then an @mention. By adding a period (or any character) before the @mention you are converting the tweet from a “reply” tweet to a “mention” tweet.
When you tweet someone directly (@mention) that tweet will appear in the feeds of users who follow both you and the user you are mentioning. Since Twitter is designed to be conversational this feature prevents your entire conversation from appearing in all of your followers’ feeds. In the example below, I just used an @mention because I was contributing to the conversation.
— Eric A. Silva (@SilvaEric1) December 5, 2014
Now for the “.@” tweets. When you add a period before the @mention your tweet will appear in the feeds of all of your followers. The purpose of this is to include the user’s handle, but not directly tweeting to them. In the example below, the purpose of my tweet is the Memorandum of Understanding signed by the three institutions. I am just choosing to include the institutions’ handles rather than just typing their names. This makes it easier for a user to click the handle to view tweets by that user. In some cases it is acceptable to use “.@mention” in a conversation such as the one above, since my response was a tip using the Blackboard Mobile Learn app.
— Eric A. Silva (@SilvaEric1) December 8, 2014
NOTE: This trick only works when you are starting a tweet with an @mention. It will make no difference if used inside a tweet.