Tweets that start with a name, do not work the way you think they do
I was put onto this interesting feature of Twitter by Scott Hanselman, where it needs repeating. When you use Twitter to send a tweet, all of your followers will see it, unless you start the tweet with a name (called an @reply). For example:
The above tweet would have been seen by everyone who follows me!
This second tweet starts with William Brand's name, so only people who follow both of us will see it. In other words, it’s only that group in the middle of the following Venn chart that will see that tweet!
So how can you send a tweet starting with someone’s name and have all of your followers see it? Start the tweet with a dot, like in the example below.
A final point to note about starting a tweet with a name: those tweets are still public. Even though your followers don’t automatically see them, they could still browse to the Twitter website and find them that way. If you want a tweet that is private, you need to use a direct message.