GoodwinThe two currencies never convert into each other. Gold Coins come with coin packages, daily logins, and promotions; Sweepstakes Coins arrive as promotional credit with eligible purchases, freeplay, and No Purchase Necessary routes.
Check the live Store before purchasing to see whether a package is eligible, the promotional amount, and the applicable terms. The wallet and current Terms of Service show any playthrough and redemption requirements; a later game load only transfers the SC selected and does not add another promotion.