In this step, you want to identify what keywords your audience uses when they research topics related to this niche market, especially searches related to their problems, pain points or deepest desires.

This information will not only tell you what topics your audience cares about the most, it will tell you whether or not there is enough profit potential in this niche.

A fun and easy too to start with is the free Google Adwords Keyword Tool. You can use it to identify the keywords your audience is using to research products, services, solutions, and information related to this niche market. 

You will need a Google AdWords account before you can use this tool. "Sign in to AdWords" -> "Create an account" (the direct url to adwords is www.google.com/adwords) . Make sure your mobile phone number is a valid one as Google will sometimes use it to send an activation pin SMS. You will get an activation mail on the email adres provided. This activation link will send you into a wizard which will trick you into setting up your first paid marketing campaign in google. Don’t enter this wizard if you don't want to provide billing data for marketing campaign! If you enter this wizard, it will insist on you providing your credit card information and you won't be able to escape from this. You need to click the small text in blue “Skip the guided set-up” instead of entering the wizard to escape the billing data step:

You can find the Keyword planner tool also in the "tools" menu of Google Adwords.
 

The keyword tool provides lots of useful data related to these keywords (especially if you use this tool while logged into your Google Adwords account) such as search volume in the selected geography, level of competition, average cost per click (CPC) and more.

What we want to pay attention when we research industry keywords is the monthly search volume. The higher the search volume, the bigger the market. As a rule of thumb, anything over 1,000 exact match searches a month is worth looking into. However, there are some niche markets with smaller monthly volume that have profit potential as well, especially if the market is hungry, and there isn’t a lot of competition.

Select "Search for a new keyword and ad group ideas" in the keyword planner tool

Let’s take the personal development market. To do so, enter your seed keyword, e.g. "Law of attraction". We don't want to deviate to broad from the context, so choose "Only show ideas closely related to my search term". Make sure you set the location and language right. If a search term has two meanings, and you don't want one of those, try to use negative keywords to eliminate that second interpretation. 

Within this market, at 240000 matches (and 57.000 exact matches for "Law of attraction") a month, globally, this is a sizeable segment of people interested in all things related to the Law of Attraction.