How long should short stories be?

Over the past two years, I have been working on my first novel, with a great deal of the time being spent on taking the plot/main characters/locations of the story and filling in all the details.  The outside details that many readers of the story won’t see much of right away; village and city names outside of the story arc, how magic works, what types of governing bodies exist, as well as creating a whole secondary world, the Abyss, and filling it with all types of creatures and power struggles, have been a lot more fun then I expected.  It’s also been a distraction because as I created this world, I wanted to further explore different parts that were outside of the main plot of my novel.  Which is how my collection of short stories (and the basis behind the title of this post) began.

A few months ago I released a collection of short stories as a kind of primer to start building a fan base or at least to get people interested in The Three Moons Realm.  The characters inside range from Zin the Imp who plays a heavy role in the first novel, to characters and races that might only be mentioned briefly in my first book.  While they have been a lot of fun to write, as each character is different, I do wonder if they are enough to justify an actual release on their own.  Which finally brings me to the question of the post.

Do casual and huge fans of reading fantasy/sci fi/anything interesting care how long short stories are?  Do you read short stories at all?  If you do, what makes you toss those four quarters to Amazon for a glimpse into a world someone else has created?

I’ve spent a bit of time looking around at short stories online, both ones for sale and ones that people have simply posted on blogs, deviantArt, ect.  The short stories I’ve found on the blogs usually take up only a few pages, while the ones ‘for sale’ have ranged anywhere between 21 pages to over a hundred pages.  Mine, according to Amazon, is 51 pasges.  So does length matter, or are their other contributing factors that make a person want to check out a new story?  Obviously the quality of the writing and the story are huge factors, but with so many new writers appearing (myself included) you don’t have an idea of what they have done and word of mouth is very rare, at least at the beginning of a person’s career.  So back to my questions.

How long do you expect a short story or set of short stories to be for your money, and more importantly, your time.

Do you prefer one ‘long’ short story or a collection of stories about different characters?

Do you even care about short stories that give a glimpse of a world, or are you more interested in only following main characters through a larger plot?

I would love to hear you’re thoughts fellow readers and writers!