I noticed that you are returning the company name in the title. https://logo.clearbit.com/fb.com .Is that intentional? Asking this because you provide a Company API too which is paid.
We are actually planning to run a referral campaign which will offer discounts based on number of referrals. I saw one such campaign getting great response recently. But the product was in a different domain and their target audience were developer s who have a bigger online presence. I will definitely try out the email approach. Thanks!
Like making user play some game on their mobile phone and giving them some discounts based on the win. The overall game experience could be designed keeping in mind the branding and philosophy of the business involved.