[O] Include TODO for once-off events?

[SabreWolfy]

I use the following to include once-off events in my Agenda:

--8<---------------cut here---------------start------------->8---
* Once-Off Task
<2014-06-11 Wed 09:00>

--8<---------------cut here---------------end--------------->8---

What is the difference (benefit) to rather doing this:

--8<---------------cut here---------------start------------->8---
* TODO Once-Off Task
<2014-06-11 Wed 09:00>

--8<---------------cut here---------------end--------------->8---

The second method gives me a red "TODO" in the Agenda and allows me to mark
the task as "DONE". Is that the primary reason for using "TODO"? If the
state of a task is not important, there is no need to include "TODO"?