User Research participant recruitment process



I want to begin a user research project to find out if there is an untapped audience for a current application related to fashion, for example people who are interested in fashion but do not know of this application’s existence. I am not sure how to go about recruiting participants for this research. Since I am looking at participants that are not currently targeted to I look at specific groups that I might think would be potential users? I was thinking having pop ups on online shopping websites asking shoppers to complete a survey in exchange for promo codes. Am i on the right track?