Additional APY for referrals or for holding longer

To increase retention and virality, it would be nice to have a referral system, and then have either a tiered APY boost (refer X friends, have them deposit X amount, and then get X bonus APY), or have a leaderboard. Be top % of leaderboard (seasonal) and get bonus APY

Either that or bonus APY the longer the lockup shown at the Deposit popup