Like Andrew said the cost savings make up for the membership cost.  Not to mention access to some product not easily found in other stores.

For those with larger families and/or "share" a membership with extended family the executive card with cash back can easily pay for the membership cost.  We usually net at least $200 - $300 in cash back after the cost of membership.

Not everything is a bargain - but it would be a rare occasion that you actually end up paying more than the sale prices found in conventional grocery and department stores.