A micro-niche is a small group of people that are sometimes referred to as a community. The people do not know each other personally, but they all have a similar interest which is what makes the niche a niche.
For example, a niche group may be a group of people who study human biology. A micro-niche would be members of that group who study cell mitosis. A micro-niche site is one that appeals to the people who are interested in the micro-niche topic.
Here are a few ways that you may be able to make money by starting a micro-niche site:
Offer services that are difficult to find elsewhere
If the service you offer is truly difficult to find elsewhere, then some people are going to be willing to pay a lot of money to have those services. The harder it is to have those services than the more you may charge. A micro-niche does mean that your target audience, ergo your customer base is small, but that is why you should charge them more money.
Give information that is difficult to find elsewhere
Sometimes even the Internet comes up short when people are searching for very specific information. You may give people that information at a cost. If people are really frustrated and have had no luck trying to find the information elsewhere, then the amount they are willing to pay will go up and up.
Offer tools that other websites do not offer
You may offer these tools on your website, and if they are useful enough for your micro-niche audience, then there is a good chance that they will be willing to pay for them. Try giving people a daily free amount of tries on your tool. People will often come to use your site again and again to the point where the free limited uses are not enough and they will pay to upgrade the service. Giving free but limited usage of your tool will also make online directories more likely to list your tool on their articles.
Sell products that are hard for your micro-niche to find elsewhere
This is going to be a real money spinner if your users are genuinely unable to find your products elsewhere. This is especially good for technological components from companies that are defunct, or components that are hard to find on the consumer market. You may really make a lot of money if you can attract the sort of person who really wants your product. Just a few sales per month may be all you need in order to turn a nice profit.
Charge people for access to your micro-niche site
If the information, tools, forums, how-to articles, etc, are very hard to come by, then some people will pay in order to access your site. This is often a case of they either pay you or go without. If you truly cannot find a micro-niche site like your own then people will probably pay for access to yours. Just make sure that you offer them good value for money.
Charge people for a subscription to your newsletter
If they like your site then there are a lot of things that you may offer them via the newsletter. Ideally, you should offer them tools, information, data or files that they are simply not going to be able to find anywhere else. Your site itself may be the trust builder that gains your subscriptions, since if your site is trustworthy and high quality then your viewers may believe that your newsletter will also be the same.
Offer micro-niche affiliate adverts that do not do well on other domains
There are going to be affiliate adverts out there that match your micro-niche theme. The trouble for the advertiser is that there will be few places where this sort of advert will do well. There will be few places where their adverts are getting few clicks. If you can find these affiliate adverts, then not only will the advertiser be eager to put the adverts on your site, he or she may also be willing to pay more for clicks.
Solicit donations to keep your rare micro-niche site running
If your site serves such a micro-niche that it is hard to make money by conventional means, then asking for donations may serve you well. People may be willing to donate for the simple fact that if your site goes offline then they will have trouble replacing you. They will not mind throwing a few dollars at you to keep the site up and running.
Charge people for asking questions via the online support system
This is done by some websites, and even though it is one of the more seedy/tacky ways of making money, it is still a possibility.
Give people a paid phone number to access further support
If people are going to ask questions of a very technical nature then it may take you a long time to answer online or via email support, which is going to take up your valuable time. If you install a phone system where you receive payments for calls to your number, then you may make money that way.