Gaining full internet access on a phone may seem archaic in the States, but in Cuba, it's been a work in progress.
And although half of Cuba's 11.2 million population own a mobile phone, not all will be compatible with the 900MHz spectrum used by the Cuban 3G network.
Users began receiving text messages in the morning from the state telephone monopoly informing them that they can buy an internet access packages for 3G service.
Only 60,000 Cubans have internet access through a limited program that allows people to connect through DSL lines in their homes, according to government statistics.
"It was about time this became a possibility for Cubans too", said Havana resident Joaquin Montiel, 58.
Cuba has lagged far behind most countries in internet access, with a combination of lack of cash, the long-running United States trade embargo and concerns about the flow of information being to blame. The cheapest plan costs about $7 for 600 megabytes of data, or more than one-tenth of what a highly paid doctor earns in a month. The country's main Internet link comes through the ALBA-1 submarine cable, which runs from Venezuela.
For years, when Cubans talked about 3G mobile internet arriving on the communist-run island, it was with the same sarcasm that people in other countries reserve for discussions of flying pigs and hell freezing over.
In recent years, Cubans have been able to access Facebook and other popular Internet sites via their mobile phones - but it often involved a combination of a special access card sold by ETECSA, pay-as-you-go public Wi-Fi hot spots and phones that were sent from relatives overseas.
Until now, Cubans could only receive and send email on their phones using cell phone networks through government accounts.
In 2015, President Obama allowed US businesses to invest in Cuba's telecom sector.
However, the government has made a decision to continue the relaxation of restrictions to Internet access, which had largely been confined to hotels and state-owned clubs prior to the start of the decade.
The government also broadcast a roundtable discussion on national TV Tuesday night, featuring ETECSA President Mayra Arevich and Cuba's communications minister, Jorge Luis Perdomo Di-Lella. As it told its customers about the new Internet access, ETECSA also warned them that in the first days of operation, "incidents could be experienced" that will disrupt service.