I think your doing it backwards. The offer should be flipped. The service home should be geared to companies that want testers. Users who want to be testers will also be able to see the link to become one and earn money. Also, consider re-submitting this because the link needs to be copied/pasted.
I am actually working on a similar product, https://testzap.com
Not launched on HN as of now .. will do that in couple if days. We already got around 500 testers will start looking for companies now.
How do both options here differ from the numerous options out there today? (One Google hit gives a long list)
I remember my company used a service, forgot the name, where you could also specify which type of users you wanted to test. How many of each, what devices, etc.