When you are going to publish your own ebook, you need to have several things covered. Beside writing the e-book, you have to format it, publish it, and advertise it. As part of this process you'll need to design an eBook cover to use for your publishing and marketing efforts.
Unfortunately this is not an easy thing to do. You can not just create a graphics filled flat document. You want to make it look like you took a picture of the cover of an actual book, so that it does not seem like it is only available in e-book form. This requires a lot of knowledge about desktop publishing and graphics manipulation. Alternately, you can hire someone that will be able to create the cover for you, but this can be extremely expensive if you create more than one.
The best investment if you are a regular writer is eBook cover software. The software allows you to easily create a cover utilizing templates in the software. You'll have access to additional fonts that you probably do not already have and you will be able to pull in your own graphics as well.
eBook cover software is a wise investment if you are going to be creating a lot of e-books. Not only do you have complete control over the project and its timeline, but you can save a lot of money by doing it yourself. It will cost you about the same amount of money to buy the software as it would cost you to hire a professional designer to create the cover. However, with the software you can use it over and over again without future costs.