You can send a lot more in the same chunk of time in a digital modulation as you can analog.
Gone are the days of the gold pressed "vinyl" record stapled to the side of
Voyager.
Off topic but related to the destination of the signal: Got any anime fans in the house? There's a series that ran in the fall, with a second season in January, called
Aldnoah.Zero. In it, an Apollo mission in the 1970s came across a hyperspace gate linking the Moon to Mars. A number of humans travelled to the red planet and built up a population of 340,000. War between Mars and Earth broke out in the 80s over control of the gate, and disaster struck, causing an apocalypse called
Heaven's Fall, where part of the moon disintegrated and struck Earth in several places, causing huge damage. In 2014, the Martian princess comes to Earth to try to form a truce, but of course, other things happen. When you talk about sending a signal to Mars, this is what I thought of.