Bloomberg recently posted a few charts on the growth of digital ads vs. traditional ad formats:

Digital is expected to become the biggest global ad segment by 2017, beating out the category's king, television, according to new Magna Global data. Currently, 38 percent of global ad spending is on TV, while about 32 percent is digital.

Global ad revenue will be about $503 billion this year, according to Magna, and is expected to increase to $544 billion in 2017.Digital media saw the largest increase in ad sales this year among competing platforms, with a growth rate of 17.2 percent. Newspapers and magazines had decreases (-8.6 percent and -10.1 percent, respectively). Growth on other advertising platforms, including TV, was basically flat. Mobile currently makes up about a third of all digital ad spending; it’s expected to be nearly half of the total digital spend by 2017.