Twitter has been around since 2006 (yes, I know, terrifying), but it still holds small mysteries.  Little quirks that some folk miss out on or misunderstand.  You might very well know them all, but if just one blows your skirts up then my work here is done.

1) HOW TO NARROW YOUR AUDIENCE
If you start a tweet with a username, then only people who follow you both will see it.  I still see relatively seasoned Twitter users do this.

For instance, if I tweet the following...

@john...