(Little) Rant : Why are They Changing Book Covers!?!?!?

Okay, so, I noticed that LOADS of books are getting their covers changed. Have you?

Examples: 

Delirium changed cover, and since I had the first cover, Pandemonium and Delirium do not match. At all.
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There's the Nightshade books
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Also, the Birthmarked covers!
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The Glow covers :

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And there are SO MANY others!

And, I'm really intrigued (AND ANGRY) about that!

I mean, what about readers who want covers (and spines) that match (like me)! What do publishers think? That we won't say anything? NOPE! BECAUSE I WANT COVERS THAT MATCH!

I mean, publishers, people don't only buy your books because of the summary. Lots of people (including me) buy books because of the cover! Some people buy the same book two times (one US and one UK) because of the covers! SO, WHY CHANGE THEM?

Also, you could at least do, if you want to keep the new covers, is also make a cover that matches the first edition! I mean, if you did that, I wouldn't even be complaining about it!

Look, I get that you change the covers to 'attract more people', but come on, the first Nightshade cover is so much prettier than the others! I mean, if you remake the covers, try to at least make them prettier than the first! I mean, isn't that obvious!

I have to admit, some new covers are beautiful; the Delirium ones and the Glow ones. The Birthmarked ones are okay, though.

And, I mean, have you noticed that more and more covers are getting changed? I mean, I heard that Jackson Pearce's series, Fairytale Retellings, are ALSO getting a make over. I mean, the books are already pretty enough! *dramatic sigh*

And so, I started wondering, why they were changing the covers. Here are my hypothesis:

1. Aliens have invaded their minds, like in The Host, and the Aliens don't like the covers, so they change the ones they don't like. 
2. Everyone got hit in the head and forgot that they had made a previous cover for the book.
3. They just don't get that it'S infuriating readers because the spines and books don't match.

I think the number one is the most plausible. Don't you think?

So, what do you think about publishers changing book covers? Does it make you angry? Sad? Or maybe you don't care? Tell me your opinion in the comments below!