Just got an email yesterday to "keep the fun going" and get another 3 months free, after my CSR membership ends on June 13. I set a Google calendar reminder to cancel after the 3 months, but I decided it was worth it.
As others have mentioned, there are times when, even after the 15% Lyft Pink discount, Uber is cheaper and/or more convenient.
I get a Grubhub benefit with the Amex Gold, so having a Grubhub Plus Membership through Lyft Pink has saved some money.
Hopefully others will get a similar offer from Lyft if they wish to continue.