[Update: Some offers mentioned below have expired. For current terms and conditions, please see card agreements. Disclosure: Cards from our partners are mentioned below.]

Following your credit card issuer definitely has some benefits. Oftentimes, the social network is the best place to learn about exclusive offers, discounts or new promotions an issuer is rolling out. Oftentimes, eligibility for these promotions or contests is contingent on tweeting out a specified hashtags. Here are a few to look out for so you can score some free tickets or great deals through your credit card company.

New York City MasterCard-holders have long been able to reap the benefits of its Priceless New York campaign via Twitter. In addition to exchanging tweets for discounts, the issuer often runs contests for different New York City experiences. Just recently, MasterCard awarded two tickets to a July Yankees game, including access to batting practice, to the first 15 customers who tweeted the correct answer to their #PricelessTrivia question. (Hashtag, of course, had to be included.)

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Those who missed out on the recent promotion should keep an eye on MasterCard's feed. In a tweet to an interested customer, the issuer confirmed more #PricelessTrivia was forthcoming.

Chase gives away a pair of tickets to a New York Liberty Basketball game every Tuesday to the first person to correctly answer a trivia question using the hashtag #ChaseTicketTuesdays. The promotion will go on hiatus during the Olympics, but is set to resume on August 7.

American Express keeps a list of all the discounts (and accompanying hashtags) available through its Amex Sync With Twitter feature on its favorites tab. This feature enables cardholders to earn special deals by linking their cards to and then tweeting from their Twitter account.

On a smaller scale, Discover tweets customized merchant deals from time to time using the hashtag #DDeal. For instance, in early July, the issuer offered 15% off entire purchases at Jos A Bank by tweeting out the coupon code DISCOVERJ.

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Image: jeffisageek, via Flickr