Lets break this down, and by "lets" I mean I'd take pointers.
Chronology of events:
1. Active users are down, new signups are down, premium renewals are down (?)
2. Number of users has coming down for some time now, and El_Jefe couldn't (didn't have enough time?) to turn it around.
3. bigWham arrives with a pound of cocaine and starts pushing the changes, of which 12-player games and Polymorphic(who chose the name?) are the best.
4. He sees no change in new member sign-ups so decides to revamp the homepage, knowing he needs to attract the kids on their phones now. He makes a design that is easier to look at on a phone and voila, new members sign up. Question is, are these kids gonna buy a membership after they see that they were fooled by the homepage into thinking CC had robots fighting every time they attacked?
The question is here, if you want to attract people on phones, shouldn't an app be developed? With an app the icon remains there to be seen all the time, and payment would be easier to make, and people would've more confident on making a payment.
Also, you could have people logging in from phones redirected to that home page and the rest to the previous homepage, not that it care much anymore because I don't look at is anymore, I just focus on the logging button and everything else is a blur, brains are amazing.
And finally here, Shannon said it and Robinette ilustrated it for you, ok, make it pop, make it stand, but it doesn't have to be ugly! It can be pretty and pop too.
And finally about
the winter and summer waves of users, Bruce is absolutely right, I've seen it to! So let's break that theory too, so the mods can understand:
Cause: People being more time at home, relying on games.
This gives you more:
1. Returning users
2. New users sign up
One cause gives you both. One cause gives you both. One cause gives you both. One cause gives you both. One cause gives you both.
Also, on the statistics provided by Dukasaur in his link, he sees 2 declines and 2 increases, but I see 4 increases for some reason. That's intriguing because although the number I always payed attention was Online Users at a time, it does not correlate with such small increases.
All this numbers could get ordered and showed in a interesting manner (on many relational outputs) for the extraction of relevant information with moderately complex sql queries but more easily done with report software. Give me the structure of the database and I make the queries for you with the condition the output be public.