If several people would be searching for something in Google, it would be highly likely to be popular. You should try using an inexpensive SEO tool to enter the requisite keywords in your specific industry for identification of the emerging patterns in searching behavior of the people.
A good strategy would be to go after the terms of the niche. There have been specific topics that may not have various search volumes. However, in event of them picking up the race, chances would be higher they would become popular in industry trend reports. You should identify these aspects in a manner to finding the particular places where your business could be filling the market gap.