Waitlist API - Quick and easy waitlist with built in referral.
Micro Work 4 all - New Website aiming to get more workers and job seekers to perform tiny task and make money.
LaunchList - Create waitlist with referral for your product launch
Picoworkers - Earn money from doing short, easy tasks similar to Microworkers. Picoworkers is the best alternative to Microworkers I ever find.
Waitlisty.io - Build excitement for your product by embedding a simple form into your website. Signups will receive a referral code to share with their friends. The more codes they share, the more they climb your waitlist.
Fiverr - One marketplace, millions of professional services.