I think one of the most important things you can do in order to achieve success in this business is to define the goals for your business and set milestones to achieving your short and long term goals. Think about the question, what would you like to accomplish in the domain investment business?
If you are looking to buy and sell domain names as a hobby, you can probably forget all about mini sites and web development. You will end up spending a lot of money on things that are unnecessary. Keep abreast of domain news, trends, and threats to make sure your business model is evolving as necessary. Continue buying good names for good prices, and do what you can to keep your costs and overhead minimal.
If you see yourself being involved in the domain business full time at some point, I strongly advise you learn about web development and SEO from non-domainers (similar to what Alan said). I may be able to share a little bit of knowledge about web development, but you really need to learn about that stuff from experts. I can help you with domain names, and I can share the things I am doing with you, but when it comes to web development, programming, SEO and other technical things, I am just learning, too, and the best advice I can give is to do what I did and research the smartest people in those fields and learn what you can from them.
For me, two years ago, I realized that it might get difficult to make a good living (for my career) simply buying and selling domain names, so I opted to go the development route. I’ve made plenty of mistakes along the way, but I’ve also done some things right. Fortunately, the domain sales business has remained pretty good, and I have built value on many of my development projects, but I am constantly refining my plans and path for the future. It’s critical to keep your eyes focused not only on the things that are right in front of you, but also on things that are going to happen down the road.
Think about it for a minute. On domain forums, blogs, news sites, corporate sites…etc, every person and company situation is different. Some people do this as a part time hobby, others do this full time because they were smart enough to register great names many years ago, and yet others are somewhere in the middle. There are people living in high tax areas and people living in tax havens. Some people are married and have kids, while others are in college or high school. We all are in different situations and what one person does has no bearing on what others should do.
How you see yourself in the future as it relates to the domain space is important, because you need to do things now to accomplish your future goals. Take some time to figure out where you see yourself and do what it takes to get there. Everybody has a different path and a different road map. What’s good today may not be good tomorrow.