It's all very well, writing your manuscript and producing a book. If you want to make it available to the public (rather than distribute it to family and friends), how does that happen?
An author website can help with that. It's a place that interested parties can read about you, sign up for your newsletter, and more importantly, see what else you've written, where they can buy the next book in the series, or a different book you've produced because they like your writing. An author website is a must.
Marketing is a skill few creative people have learnt. Stories are created; books are sold. Just because you've written a book, and you have a web presence, it doesn't mean buyers will beat a path to your door. You need to tell people about your book, where they can buy it, and why they'd want to buy it. But sales and marketing is a tricky business. Be too pushy, and you will drive purchasers away. We at author.support monitor the most productive methods for selling your books - whether to advertise or not, whether to give samples away, whether to do book signings, whether to sell your books on a market stall ... all these methods, and more, are identified. Their effectiveness is evaluated, and you will receive the best advice for your book.