Almost every casino has Facebook, Twitter, Foursquare and SMS-text based platforms to let you know what they have to offer and to send you special discounts and promotions.

MGM Resorts has also created iPhone and Android apps with casino details and special offers. They are basically miniature versions of the casino’s full website (including property maps so you can find your way around!). The apps even let you make room and dining reservations. MGM Resorts has made a separate app for each of their casinos. If you are only interested in their shopping or entertainment options, they have the Shop MGM Resorts and the Entertainment of Las Vegas apps just for that.
Click here for the full list of MGM Resorts apps and links to the Android and IOS versions.

Caesars Entertainment decided to put everything together in its Total Vegas app. It includes info on all of its hotels and casino, their dining, retail and entertainment options as well as your Total Rewards account information. The app also has a link to their SMS-text message offer system.
(update: Total Vegas has been replaced by the play by TR app.)

The standard setup of SMS-text based promotion systems is for you to text a code to a specific number and then you will start to receive a few offers each day for that casino. For MGM Resorts properties, once you opt in, you will get messages until you opt out. The Caesars Entertainment system will send you messages for 3 days and then automatically stop. You can restart the messages by opting in again. Similar to their approach to the mobile apps, MGM has a different number for each casino. Caesars Entertainment uses one number for all casinos, but uses different codes to activate them. I have the latest codes listed below, but you can find updates on the Caesars SMS page. Typical offers include dining discounts ($5 off buffets, free appetizers), entertainment and attraction discounts (50% off show tickets or entry fees, seat upgrades) and nightlife discounts (free nightclub passes, 2-for-1 drinks).

Another handy SMS-text promo to follow is the Tix4Tonight ticket discounter.
Text T4TOFFER to 56242 to get daily show and dining offers as well as $2 off of their ticket processing fee.

The latest trend seems to be casinos creating Foursquare badges that give you a perk like a free drink or line pass for checking in to a few establishments at their casino.
The Luxor gives you a free pass to LAX for following the Luxor on Foursquare and checking in to 3 different categories of its venues in 2 days. For example, checking in to the Luxor Hotel, MORE Buffet and Centra in a 2 day period will unlock the badge and give you the pass. This is in addition to whatever promos are available at the individual locations. Simply checking in to the Luxor gets you a 2-for-1 drink offer at the Aurora lounge.

Mandalay Bay’s version gives you a free fur upgrade at the Minus5 bar at Mandalay Place.
New York – New York’s version gets you unlimited VIP admission to The Bar at Times Square and Nine Fine Irishmen.
The Mirage version gets you VIP admission and a free drink at King Ink.
The Cosmopolitan version gives you a VIP line pass for the Wicked Spoon buffet.
Monte Carlo’s gets you an unspecified VIP experience at The Pub.

Total Rewards is running the Escape to Total Rewards promotion where you get additional entries by using Foursquare to check in at various Caesars Entertainment locations or by visiting their Facebook pages.
UPDATE: The Escape to Total Rewards promotion has ended.

MGM Resort’s Mlife players club has partnered with TopGuest to give you 500 Tier Credits each day for checking in via FourSquare. You need to link your TopGuest and FourSquare accounts and add your Mlife account info to TopGuest for this to work.
UPDATE: On August 31, 2013 Mlife ended its partnership with Topguest. You will no longer receive Mlife Tier Credits for checking in. Topguest was bought by Switchfly in 2014 and checkins no longer accrue points for any of the former TopGuest partnerships.

Happy Social Savings!