77/264 For the quarters ended December 31, 2017 and 2016, our Users streamed 11.4 billion and 7.7 billion hours of Spotify content, respectively. This represented an increase of 48% and 51% as compared to the preceding fiscal year quarters ended December 31. The increases were due principally to an increase in our User base as a result of our continued investment in driving the rapid growth of our service, both through geographic expansion and consumer marketing. Results of Operations Revenue Year ended December 31, Change 2015 2016 2017 2015 to 2016 2016 to 2017 (in € millions, except percentages) Premium 1,744 2,657 3,674 913 52 % 1,017 38 % Ad­Supported 196 295 416 99 51 % 121 41 % Total 1,940 2,952 4,090 1,012 52 % 1,138 39 % Premium revenue For the years ended December 31, 2016 and 2017, Premium revenue comprised 90% of our total revenue. For the year ended December 31, 2017 as compared to 2016, Premium revenue increased €1,017 million or 38%. The increase was attributable primarily to a 46% increase in Premium Subscribers, partially offset by a decrease in Premium ARPU of 14% in each case, as noted above. For the years ended December 31, 2016 and 2015, Premium revenue comprised 90% of our total revenue. For the year ended December 31, 2016 as compared to 2015, Premium revenue increased €913 million or 52%. The increase was attributable primarily to a 71% increase in Premium Subscribers, partially offset by a decrease in Premium ARPU of 9% in each case, as noted above. Ad­Supported revenue For the year ended December 31, 2017 as compared to 2016, Ad­Supported revenue increased €121 million or 41%. This increase was due primarily to a 31% increase in the number of impressions sold, driven largely by the growth in our programmatic channel (i.e., impressions sold using an automated online platform), which accounted for 49% of sold impressions and grew revenue 100% year over year, accounting for 18% of our Ad­Supported revenue. Ad­Supported revenue growth also was driven by a 7% increase in the average rate per impression, as our premium video offerings outpaced overall growth, growing 74% and reaching 29% of Ad­Supported revenue. For the year ended December 31, 2016 as compared to 2015, Ad­Supported revenue increased €99 million or 51%. This increase was due primarily to a 50% increase in average rate per impression based on the product mix sold during the year, as the number of impressions sold was approximately flat with the previous year. We curtailed the number of desktop impressions in order to promote mobile formats (which account for nearly 50% of Ad­Supported revenue) and higher value desktop placements. Growth of programmatic impressions offset the decline in desktop impressions. 70