One of the many reasons will be to make their product stand out to the buyer, this is in a market place where choice is king and (via the internet) where a consumer has countless buying options at their finger-tips. But standing out for any reason simply isn’t enough, you need to be able to present an idea in a fashion which will relate to your target audience (and yes your book will have a target audience too).
A target audience is something that a few authors make the mistake of not considering when launching their book, if you make the assumption that the book is for ‘every reader’ then it will cost you sales. It can be hard to think about but the fact is that not everyone will like your book. And this is a good thing, understanding that your work will appeal to some more than others will enable you to target those who are more likely to buy it.
Once you have considered who will be reading your book the book cover design and advertising will become more focused and effective, it goes without saying that certain design styles are expected for specific genres of book, for example, if your book is aimed at younger children then it’s more likely that the cover will contain brighter imagery and illustrations, as opposed to horror fiction which will of course be a lot darker.
So there are expected styles for specific genres, all done to help the buyer understand (in a split second) what the book is about and if it will appeal to their tastes, however, there are always exceptions to any rules and these boundaries are always being pushed by designers. The key point is that the cover design you choose to represent your book works in delivering a message, connects to the reader and represents your manuscript professionally.
If you already have a book published how do you know if your cover is working for you? This can be a thorny subject for some authors (especially if they created the cover design themselves), realistically there is only one way and that’s in getting honest feedback. Family and friends may not be the best option here either, ideally you need an unbiased perspective upon your cover, we’d always recommend writer’s groups and some forums to ask but speaking to a professional is always a good option. Getting in contact with designers can work as long as you’re honest with them, if you are not in the market place to buy a new design let them know (but don’t waste their time – most designers are busy people too).
It is of course best to start off with a professional design made for you (and they are far more reasonable than you may realize too), launching with a great cover and some advertising materials will enable you to launch your book professionally, it sets out your position as a serious author and that your book is in the same league as those from the exclusive publishing houses.