Researching a novel can be fun or frustrating, but it's always time consuming and, all too often, the facts that you find the most fascinating never make it into the finished work. That doesn't mean that the hours spent checking websites, hunting out books and talking to experts are wasted.
    The more background information you have, the more confidently you can write. You'll know your characters better and won't have to waste time rewriting because you've placed them in impossible situations.
    More than this, you can use what you've learned to write features for magazines, blogs, etc. If you've researched women bus conductors in World War II for a novel, you could think about writing a feature for a history magazine or a bus/public transport magazine, women's magazine and so on. The things you turn up in your research will give you ideas for more. Be creative and lateral in finding different angles and you'll come up with even more markets. Not only could this provide a useful addition to your writing income, but every published piece is an opportunity to promote the novel for which you did the research in the first place.
    Nothing need ever be wasted!