When someone on Instagram clicks on a hashtag under an image, it goes to the stream of images containing that hashtag. This means that thousands and thousands of people can see your image by clicking on a simple word you type!
You can also find trending and popular images by searching different hashtags. It is a way to gather photos themed around similar topics. Many people use hashtags to chronicle weddings, vacations, blogs. For instance, my Rhode Island adventures are filed under #oceanstatecait while my pictures of my pup can be found under #littleladydakota.
The basic line is, if you hashtag strategically, more people will see your account and interact with it and possibly follow you. If you can see what your competitors are hashtagging and what popular pages that are in the same genre as you use, you will be able to benefit. Use similar hashtags as those in your industry if they are pertinent to the image you post and see how the work out.
Need advice on which hashtags work best for your account? Need to create a company hashtag? You can always hire me!