When you write personalized newsletters you are probably familiar with the {firstname} and {lastname} tag. If you use both you should replace them with {fullname}

If you have for instance only the first name of your subscriber and you write

Hello {firstname} {lastname}!

The message will look like
Hello John !
Doesn’t look good if the exclamation mark is separated from the name. Better use

Hello {fullname}!

which looks like
Hello John!
Much better!

Keep in mind that you can use a fallback string if neither the first nor the last name is provided:

Hello {fullname|my friend}!

So you get always a personalized message