Why do people do this on twitter?

[.]

They put hashtags at the end of their sentences. This is an example... I saw this quote on clevver tv by Miley Cyrus, "now that I'm engaged I can't have friends of the opposite sex to hang out with? #dumb" I still don't get it.
I'm asking what's the point. What does it mean??

[Rat]

Why not?

[Janelley]

Cause hash tags are the best!

[screechingbeam585]

Because they can

[Fontaine]

It's just what people do...it makes them get more views on their tweets by putting popular trending hashtags

[cooinghobbies107]

Because they can. #SWAG #YOLO #LOL

It gets annoying in my opinion.

[Bradley P]

Hashtags are like the topics, or keyword links, you see on a weblog--you can click on them to see other material organized under that tag.

For example, in the Tweet you gave, people would be able to click on the hashtag and see other recent Tweets that were also filed under "dumb". Granted, different websites do this differently and with Twitter it's also a popularity contest, but that's the basics of it--you use hashtags to find other Tweets on a similar subject or point.