With same-store sales down 7% in the U.S. during the most recent quarter, KFC is attempting to transform itself into KGC.

KFC has been a trending topic on Twitter most of the week thanks to coupons announced on The Oprah Winfrey show on Tuesday, May 5 for two pieces of chicken, two sides and a biscuit. The coupons could be downloaded at UnThinkKFC.com until the end of May 6.

KFC then announced on May 7 that due to “overwhelming response” it can no longer accept the free coupon, but will introduce a rain check program to take care of inconvenienced customers.

KFC’s promotion quickly turned into an exercise in crisis management as long lines and angry customers shared their experiences online. Overall online chatter around KFC has been generally positive following the announcement.

Though the positive chatter has trended slightly down over the past two days while negative chatter has trended up.

This giveaway is KFC’s second national giveaway in the last two weeks. The chain declared Monday, April 27 “UNFry Day” and gave away 4 million pieces of chicken. In addition to a full-page ad in USA Today, KFC also unveiled a new ad campaign with a TV spot produced by Academy Award-winning director Errol Morris containing endorsements from celebrated chefs Sandra Lee, editor-in-chief of Sandra Lee Semi-Homemade Magazine, and TV One’s G. Garvin. Despite all of these tactics, the Oprah promotion generated considerably higher chatter for KFC than UNFry day. So marketers take note — free food isn’t exciting enough to talk about unless Oprah is involved.

As a point of reference, we compared KFC chatter to McDonald’s, the fast food chain typically generating the largest amount of chatter online. KFC spiked past McDonald’s during both promotions. But can KFC sustain chatter in the long term? Will customers like the grilled chicken enough to go back and keep talking about it when they have to pay for it?