Costco promotional membership deals for new and existing members

Costco has great some great deals for both new members and existing ones:

• New members, buy a Gold Star Costco membership online and receive a $10 cash card when you enter promo code 1080GOLDSTAR at checkout.
• New members, buy an Executive Costco membership online and receive a $20 cash card when you enter promo code 1080EXEC at checkout.
• Existing members, refer a friend to a Costco membership in-store and receive a $10 cash card.
• Existing members, enroll any American Express card in automatic renewal in-store and receive two months of free membership (value $8.34 for Gold Star members, $16.67 for Executive members)

On the fence about whether the cost of a Costco membership is worthwhile?  Please read here about our decision process for joining Costco here, and also about why buying an Executive Costco membership is a no-lose venture.

Hat tip:  Dans Deals