Did you know that if you start a tweet with the @ symbol, it will only show up in the Twitter timelines of you, the person you're @-ing and the people who follow both of you?
It's true. Of course sometimes this comes in handy, but if you want all of your followers to see your tweet, start it with other words or .@ instead.
From Twitter's Help Center:
If you write .@Support or ?@Support, it will appear as a regular Tweet, meaning all of your followers will see it in their timeline, rather than just you, the intended recipient and those who follow both of you.
Now ya know!
Read all my Twitter tips.