Where «Come to the dark side, we have cookies» comes from?

I have been spending too much time lately on internet, just reading site by site, without any goal, just clicking in each link that was under the mouse’s pointer…. and after some time I found a "strange" thing. It was a popular (sub-culture) sentence that you could find all around internet. I realize that a lot of people use it, even earn money with it, or  they just use it for the title of their website or blog. Even as a tag of a nick name in forums, and it surprised me because it was popularly used and I didn’t know where it came from.
So, as Morpheo said in the ‘Matrix’ "You feel something strange but you don’t know what is it", I felt the same about this sentence; "Come to the dark side, we have cookies". What is it? Why is it soooo famous? Where does it come from? Why people sell t-shirts with this sentence (another site)? Why there are icons, pictures, cups, etc about it? and Why it looks sooo comercial, so funny, sooo interesting,… it is totally a catch phrase. For all of these, I began to investigate…

Of course, when you hear "Come to the dark side…" the first thing that come to our mind is Star Wars so I decided to begin in this point. "Come to the dark side…" makes sense. Darth Vader told it to Luke Skywalker…. And we all know how did the story end. In fact, in order to be more precise, almost to a freaky-star-wars level, Darth Vader said as follows: "Come to the dark side,… together we will rule the galaxy". wowww, a tasty proposal, difficult to reject,… but luckly (or not) Luke didn’t accept.
Today, I wander what would had happened if Darth Vader would had said: "Come to the dark side, we have cookies". Maybe Luke would had answered "YES" without any doubt and I would had found finally the origin of the sentence. But this is not the case…

Some people in internet assure that the origin of the sentence is from a famous rock song, however anybody remember the name of the band or the title of the song, and others assure that the sentence was taken from a book, an unknown Lovecraft’s book probably, but I wouldn’t bet hard for it, although you can always find very interesting and impressive phrases in books…

Of course, you can always find the "silly" answers which I didn’t take into account (which it doesn’t mean they could not be the real origin of the sentence)… Inside this group you can find Harry Potter and Stargate stuff,…  I don’t think they are serious answers of the question because the sentence looks much older than these stuff (according the time it looks have been used since). So if the sentence appears in harry potter or Stargate is because they take it from somewhere else…

The sentence has not copyright, so the possibilities of an advertisement sentence didn’t convince me either. So, I found myself at the starting point again. Star Wars looked the most likely origin of the sentence, but in fact IT WAS NOT. Maybe it began there, in Star Wars, and then somebody added "we have cookies", but… who? Who raised the sentence at the level of the "stars"…

…….

Of course if anybody know the answer of the question, I cheer him/her up to send a comment and bring some light on this mystery. I would appreciate it a lot .

My own opinion, after all the time spent on it , is that maybe the idea was in fact taken from somewhere else (probably a movie, probably Star Wars) and it just grew up in the urban culture, mouth to mouth, because it was fresh, it was funny, it was a catch phrase.  Is like those kind of things that a friend explain you and in a bit, without to be aware of it, you are explaining it to somebody else, or just using it in any other place. Thus, it has become a popular sentence around all the world, used in every single object, made FAMOUS by all US, moreover in internet, where the impressive and powerful sentences to call the attention of everybody are very well appreciated (and not only in advertisement or business but in applications and services as Messenger, sites or forums as well).