Need help to grow a practice exam site

hi all, i have developed this site with practice questions for a few certifications. Some questions are drafted by me and some submitted by users. for some premium questions there's a small fee that gives you access for a few months. i am starving for ideas on how to promote the site and increase it's reach. The content is good (i believe), i also have heard some good reviews from people saying that the practice questions helped them succeed in the exam. Any ideas are welcome.. also if anybody wants to get involved to help/grow the site, please reach out to me.