Aneesha Dev, author of Stan's Jams, shares some insight into the differences between self-publishing and traditional publishing.
Self-publishing can be a bit of a game. The main thing to remember is why you're writing: do you want to see your project on the shelves of major bookstores, or do you just want a keepsake of all your hard work?
Self-publishing is great. It allows you to have full control over the content, design, layout, and presentation of your book. Whichever company you decide to work with can be involved as much or as little in the decision-making process as you want. Essentially, if you’re working with a self-publishing company, you’re paying them to follow your guidelines, and you don’t need to seek their approval as in traditional publishing. In return, you will have a visually appealing product that you can share with family and friends, with the added benefit of using their online retail resources (ie Amazon, Indigo, etc) to make your project as widely available as possible.
However, self-publishing does have its limitations. Your work will very likely never be seen on any bookshelves in any bookstore. It is financially supported entirely by you, and all the legwork is done on your own. Self-publishing companies, in order to make more money, tend to dangle seemingly too-good-to-be-true opportunities in front of you, most of which are marketing gimmicks aimed at your desire to get recognition. The result is often an expensive investment on your part, with a result nothing like you were anticipating, so watch out for that! If you want your project to be known around the world, available in stores, and marketed to the right people (ie newspapers, magazines, etc.), self-publishing probably isn't the way to go.
Traditional publishing, on the other hand, will probably get you that kind of recognition. It typically involves using an agent, someone who has connections to the right people in the right places and who does the majority of the legwork. Their job is to get your work out to the right publishing houses, though they cannot guarantee it will be accepted. If a publisher likes your work and agrees to take it on, they tend to have more of a say in the content and how it’s marketed.
All in all, self-publishing gives your writing a face, and can produce high quality material. But getting worldwide recognition is highly unlikely. Traditional publishing can get your project where you want it to go, but involves more middlemen, and depends on an outsider’s opinion. So it’s important to really think about what you want your writing to become, and take the course that will get you there.