Now it's too early to think about a referral program. We have not even started with ads too.
The answer to this question is in the question body itself. Once the site gets popular we should think about a referral program. Now a lot of back end works are pending there to meet future traffic , moderation , managerial activities etc. Once it's the right time, more programs or better changes in earning system will be introduced. Now need more statistics about how the posts are reflecting on searches and on user engagement areas.
You are always welcome to share more interesting ideas either by asking questions or by using 'send feedback' form. Thank you