G'day,
Purchase a 12 Month PS+ subscription on PSN Store (US) during March and you will be emailed a 3 month voucher before April 14.
From PSN Store:
‘BUY 12 MONTHS, GET 3 MONTHS BONUS’ Promotion valid to legal U.S. residents between 3/16/17 - 3/31/17. Limit one promotional offer per person. Additional purchases will be void. Sales tax may apply. Promotional offer is non-transferable and non-stackable.
You will receive this PS Plus membership for 12 months, with an additional 3 months via a voucher code. Voucher code will be sent to the email associated with your PSN account. Voucher codes will be delivered no later than April 14.
Cheers.
Insane, thanks OP. There hasn't been a decent PS plus sale for almost 2 - 3 years. Miss buying USD30 12-month subscriptions.
Having said that sales prices with US PLUS aren't quite what they used to be and Flash sales are no longer USD1.99 per game.