If you want to get 500 users for your SaaS for free:

1. Make a free job posting on Linkedin 2. Make it explicit: ‘volunteer role, no pay' 3. Recruit beta-test volunteers for your startup 4. Redirect them to Google form and collect emails 5. Set up a Zapier automation to send emails to applicants for them to test the web app P.s. Repeat step 1 every 6 hours. Linkedin free job posting caps out at 150 views (the algo de-ranks after that)