Why do websites update the theme of there website?

There are some websites that built traffic with theme of there website and most people enjoy that theme. Not the one that they change to most of the time. Such as gizmodo. They changed there theme and many people didn’t like the new feel. Why do companies do this? Does this increase the views of traffic to your website or does google page rank like this?
Answer #1
Oh, I didn’t know that.
Answer #2
I must comment something..
This is yours 100 thread about your website… Dude, you are really pain in the ass! (sorry but you are)
You have website (ok, cool), but you won’t make money like Gizmodo (or similar, you are little to late)… There are tons and tons of websites so why do you think that yours is special?!
Please, stop bothering us with stupid questions… Half of the answers you can find using Google search!
Answer #3
New look and feel. Its an upgrade. Why do companies change their logo’s? For a newer, more stylish look.
If you browsed the web in the 90’s, you would understand why the web changes and adapts.
wo_Ot? replied: Half of the answers you can find using Google search!
This right here ^^^