If you use your Starbucks card to make a purchase on 6/26 you’ll get Gold status for a year.
Since Starbucks devalued their rewards program the only real benefit of Gold status is the ability to earn stars which are redeemable for free drinks.
Gold members get a free drink for every 125 stars earned and earn 2 stars per dollar spent. That means a free drink for every $62.50 spent, though promotions are also offered to earn bonus stars.
Normally you need to earn 300 stars in a year (in other words spend $150/year) for Gold status, but with this promotion you’ll skip right to Gold with one purchase.
This promotion won’t extend your status if you are already Gold.