For the Gold SkyMiles Card (personal or business), you will receive 50,000 miles after you spend $1,000 within 3 months, and a $50 statement credit if you book a Delta flight within 3 months. The $95 annual fee is waived for the first year.
For the Platinum SkyMiles Card (personal or business), you will receive 50,000 miles and 15,000 MQMs after you spend $1,000 within 3 months, and a $100 statement credit if you book a Delta flight within 3 months. The $195 annual fee is not waived. You do get extra perks such as an annual companion pass with the Platinum SkyMiles Card. So if you value the MQMs, extra $50 credit and the additional perks, you may want to choose Platinum over Gold SkyMiles.
Landing Page for Personal Gold and Platinum SkyMiles Cards
Landing Page for Business Gold and Platinum SkyMiles Cards
Application Page for Personal Gold SkyMiles Card
Application Page for Personal Platinum SkyMiles Card
Application Page for Business Gold SkyMiles Card
Application Page for Business Platinum SkyMiles Card