Apple Music is giving a free month to some who tried the three-month trial but didn't subscribe13
In notifying those who are receiving the offer to return for a free month, Apple says, "Come see what you’ve been missing in the new Apple Music, like a simpler design that makes finding what you want, and discovering new music, easier than ever." That is leading some to speculate that the offer of a free month is going to those who subscribed to the three-month trial before Apple Music's redesign in 2016. In giving some former trial members an additional free month, Apple is hoping to convert some of them into paying subscribers once the month is over. Those interested in taking Apple up on the offer will receive a promo code allowing them to receive the free month of Apple Music service.
In the streaming music industry, Apple Music trails only Spotify, which has over 70 million paid subscribers and has another 90 million users listening to streaming music through its ad-supported free tier. While Apple Music doesn't offer a free level of service on a regular basis, it does have the three-month trial, which is something that Spotify does not offer. It should be pointed out that Spotify had a huge head start over Apple Music; the former is over 9 and a half years old while the latter will turn three this June.
Apple and Spotify both charge the exact same rates. Individuals pay $9.99 a month, while a family with up to 6 members is charged $14.99 each month. College students can sign up for a special monthly rate of $4.99.
source: Reddit via RedmondPie