Continental Airlines is joining the buy-on-board menu wars with specialty cocktails. The airline announced Wednesday that  it will start selling mojitos, pomegranate martinis and Red Bull energy drinks.

Starting Thursday, customers will be able to buy the drinks with alcohol for $9 and without it for $3.Continental joins other airlines in getting creative with the drinks they’re selling, going well beyond mini bottles of booze. Southwest Airlines sells a $4 screwdriver, a mix of vodka and orange juice. Delta sells a $7 Five O’clock Somewhere, a mix of rum, orange juice and cranberry-apple juice.

Though airlines charge for alcoholic beverages, such as beer and wine, the new drinks are the latest effort to increase revenue. In the last two years, airlines began to aggressively charge fees for services that were once free, including checking in bags, changing seats or flying stand by.

Henry Harteveldt, a travel analyst with Forrester Research, said airlines look at the fees as a way to add revenue. The trend started in 2001, he said, when airlines stopped offering meals on flights shorter than three hours. And since then, they have found ways to add more fees.

“(The airline) industry operates at the latest common denominator,” Harteveldt said.

Continental announced in March it would stop serving free meals for U.S. economy class travelers this year. Instead, it would sell sandwiches and other meals. The company said the move came after its U.S. competitors did away with the meals or started selling them.

In the first three months of the year, the nation’s 10 largest airlines collected $1.86 billion on ancillary fees, which includes baggage fees, reservation change fees and revenue from frequent-flier programs, according to the U.S. Department of Transportation. Nearly $770 million came from baggage fees, a 33 percent increase from a year earlier.

Sales of food, drinks, pillows, blankets and entertainment on flights are not reported separately by the Department of Transportation.