If only you could build a valuable product with nothing more than a list of email addresses.
Linking email addresses to facebook accounts to groups they're involved in and developing target markets for certain users and selling those lists (ex. gamers) to less-than-reputable and maybe even reputable marketing companies seems like it could be profitable... Maybe I'm naive?
1. Find niche on facebook
2. Find appropriate nice product with affiliate scheme
3. Harvest Emails
4. Send email with product ( low conversion, but who cares? )
5. RepeatMany reported this, but it was not eligible for bug bounty, it was a feature according to FB, even though it circumvented their pay 1$ to deliver your message to someone you are not friend with.