Many business owners start a business, expand and/or add products and services based on a hunch instead of real data!
What is the size of the market?
It is imperative to know how many potential customers are out there.
You can use the search engines to gather the overall data but small businesses find it difficult to translate this to there business. An easy way to test a market is to do a market test using the internet.
Amazon and Ebay will show you what is hot and what products sell for.
If you have a email list; there are services that will conduct send out and gather the survey information for you. If you do not have a list; put the survey out on social media. If you keep it short and to the point people will respond and gladly help. You can also offer some give aways for completing the survey; these can be obtained for as little as $100.
Out of stack sale:
List your product or service on the internet and promote it; then when the potential customer reaches your checkout page simply post a note saying that you are currently out of stock but will have product available on a future date; ask them to submit there contact information if they would like to be contacted when product is available. You can then measure the hits to the site, the amount of time spent on the site and how many provided there contact information. If the number is large enough then move forward. Some will suggest having the customer checkout and pay and then be told that you are out of stock but will fulfill the order within x days. While receiving money always sounds good, I would not suggest doing this! At worst it is illegal in some states to conduct business this way and at best you will appear as a scammer and hurt your reputation and ability to ever do business with these potential clients again.
Testing the waters will save you a lot of time and money as well as identify the winners that you should spend time on and the losers that you should walk away from.