A child once turned orange from drinking too much Sunny Delight. The company used Beta-Carotene (found it carrots) to color the drink which can make you orange at extremely high doses. The girl was drinking 1.5 liters a day.
Claud Hatcher bought a large amount of Coca-Cola syrup from a salesman and thought he deserved a reduced rate for the amount. When refused, Hatcher vowed to never purchase Coca-Cola again and was determined to develop his own soft drink. He kept his vow and today we have Royal Crown (RC) Cola.
Coca-Cola released a drink, Tab Clear, with the sole intention to be marketed so bad, that people wouldn’t want to drink it, in an attempt to ruin sales of Pepsico’s equivalent, Crystal Pepsi, by comparison. It worked.
A pair of soft drinks were sold in Singapore called Anything and Whatever. While each offered six flavors, the cans were identical, so you didn’t know what flavor you were going to get.
Vernors is actually the oldest soda still being sold. It predates Dr. Pepper by 19 years.
There is a little town in Mexico called Chamula where shamans started using Coca Cola in their religious rituals to heal worshipers. Pepsi heard about this and began giving commissions to shamans if they recommended Pepsi instead, so then Coca Cola did the same and there are now rival religious groups based on which soft drink they use.
There is a cola named OpenCola witch is open source. The instructions for making it are freely available and modifiable. Anybody can make the drink, and anyone can modify and improve on the recipe as long as they, too, license their recipe under the GNU General Public License.
A fictitious soft drink was created to prove the effectiveness of advertising on buses. So many people started demanding it that the drink actually starting being made by restaurants and soft drink companies.
Before Orbitz.com was a travel site it was the site of a soft drink that had balls of jelly suspended in it.