What does this mean on twitter?

[MissSunshine]

Okay, maybe I'm stupid. But what does it mean on twitter when someone posts a whole bunch of >>>>>>'s or <<<<<<<<<<'s ?

For example: my friend posted something like this.

The fact that I'm graduating with sixteen more credits than I need <<<<<<<<<<<< (or it may have been >>>>>>>>>>>>>>>) no sure.

What does this mean?! I feel so stupid. Haha.

[Alex Ryan]

>>>>>>>> means they like it
example: Getting ice cream instead of seeing the doctor >>>>>>
<<<<<<<<< means it sucks
example: Failing 2 classes and being grounded over spring break <<<<<<

Twitter is crazy