It is important that you attempt to maximize the potential of each business you begin, but you should start by spreading your income base quickly by setting up four or five small online businesses and focus on expanding them later. Using public domain products, this approach is fairly easy and quite successful. 

You can pick several public domain works, create a different product for each of them, and after you have set up individual websites for each product, return to improve and expand on each website. This will allow you to generate multiple income streams and then maximize the income potential of each stream within a short period of time. 

So many people think of the public domain for starting a new business that they forget the most important aspect of using the public domain – instant content. If you already have a website or blog that can use supplementary content, use the public domain for possible subject matter. Not only can such new content be used to increase any AdSense income you make, but it can also 'sell" your other products and services by building your business reputation as an expert. 

It's not always possible to find relevant content. Information on the latest computer or DVD technology is unlikely to be in the public domain, but there are many niches that have timeless appeal. Woodworking or cookery, for instance, are popular subjects that have a timelessness about them. They were popular ten or twenty years ago and they will still be popular in another ten or twenty years. If you operate a business that works in 'timeless" niches, the public domain can become a far better resource than any ghostwriter you can ever hire! 

When you begin an internet venture, it is a good idea to choose your first business from within your own hobbies and interests. Many people share their hobbies and interests, and if there are enough people like you searching for information on these topics, you could quite easily make a lot of money. 

This advice is both good and bad. While it is helpful to start a first online business in a niche that you have an interested in, it's often the case that these niches are not very profitable. There might be too much competition, for example, or not enough demand, or there may not be any buyers for your product in that market. 

Hobbies such as cricket, playing poker, crochet patterns or even architecture, on the other hand, are excellent avenues for starting small websites using public domain material. By using public domain works that outline everything from playing tips to history and immediately usable information, you can carve your own little niche and not only build yet another income stream, but enjoy yourself at the same time. 

On a final note, you should assess your current resources (your business and your hobbies) to see how the public domain can bring in new income opportunities for you. Importantly, you should continue your education by reading as much on the subject as you can.