When Copa America starts on June 3, it will incorporate goal line technology in the form of Hawk-Eye's camera-based system.
The Copa Local Organizing Committee selected Hawk-Eye, which is already in use in several leagues, and was used last summer in the 2015 Women's World Cup.
Goal line technology was also used in the 2014 Men's World Cup, although that was a different company, GoalControl-4D.
Hawk-Eye puts cameras around the goal and connects them to tracking software to indicate whether or not the whole ball has crossed the line. If a goal is scored, then the system sends a signal to the referee's watch.
You can see how the Hawk-Eye system was used in the 2015 WWC in this goal-line clearance from Meghan Klingenberg.
Back in 2013, it was estimated it would take about £250,000 to install Hawk-Eye for each club in the Premiere League, or about $400,000 in 2013 money. In 2014, the Bundesliga said they wouldn't install Hawk-Eye or similar tech because ti would cost each club about €500,000, or about $675,000 in 2014 money. Clearly there's some variation going on here, but using the lower figure and accounting for inflation, $400k per stadium across 10 stadiums makes for an estimated US $4 million price tag.