Referral links. Open the user menu (your profile picture, top right) or the referral badge on the main toolbar to copy your link or code, then share it. Everyone who signs up through it stays attributed to your account. As your referrals grow, your account moves up the referral tiers, which raise the screener's limits and refresh speed. Your tier and your progress are under Referrals in the user menu, and the tier table is in the Referrals overview.
Gift codes. Open the plans page (profile picture, Subscription, OpenMarket +), enter the code under Have a code? and choose Redeem. The page confirms how long Plus is active.
Partner links. If you arrive through a partner's referral link, the plans page shows any discount that comes with it before you check out.