Thank you for the personal perspective. I make the assumption that by sole proprietor you have it structured as an LLC? This seems by my research to be the best general way to create a simple business entity.
Developing your marketing may help you make the impression (stake your claim) that you are that service- the others just echo your operation. But if someone doesn't know to think of you first when they need your service, you're easily usurped. Making a strong impression to your market matters as much as tour technology sometimes.
You answered your question with your own final sentence:
"I have a huge passion for the web and learning new things."
That's exactly what you should focus on. What catches your eye? Read up on the why's and what-for's of each faction of web reality, from data storage to real-time GUI processes. See what you think is most exciting, or which elements of the "real world" you want to be a part of, and see how technology helps them do their work better.
I hope you continue the path you are on: whatever direction you take, you will be ahead of the many around you that don't have that Passion. Match your work to your passion, and you can not help but excel-
I think an important element to good audio retention is the intentions of the writer. If a book is written by a skilled writer, in a fluid, conversational manner, then a well-read dictation of it will likely be more enjoyable and carry higher retention.
There are some books (writing styles) that just don't translate to speech well. I believe that is more the writer than the content. A technically brilliant author can write in such a way that its impossible to follow word-for-word spoken, while his methods make perfect sense on the page.
Good topic OP- I have a few back-burner ideas involving audio components in web environments, and this area has always been of interest.