Joining a user testing campaign is fun and simple, but absolutely not an easy job since it requires various factors from the tester to full fill before being chosen to become one. Becoming a user tester is relatively straightforward and can be done by following these steps:

1. Research user testing companies: There are many companies that offer user testing services, such as UserTesting, Validately, and TryMyUI. Research these companies to find the one that best fits your needs and interests.
2. Sign up for an account: Most user testing companies have an online sign-up process where you can create an account and provide some basic information about yourself.
3. Complete your profile: Once you have an account, complete your profile by providing as much detail as possible about your background, skills, and interests. This information will help the user testing company match you with relevant testing opportunities.
4. Complete a sample test: Some user testing companies may ask you to complete a sample test as part of the sign-up process. This test will give you an idea of what the testing process entails and help the company assess your skills and suitability as a tester.
5. Start testing: Once your profile is complete, you can start testing. You will receive email notifications when testing opportunities are available, and you can choose which tests to participate in based on your schedule and interests.
6. Provide feedback: During each test, you will be asked to provide feedback on the product or website you are testing. Make sure to be as detailed and honest as possible in your feedback to help the company improve its product.

By following these steps, you can become a user tester and start earning money by providing valuable feedback on digital products and services.