Sudden Rating Spike

So for several weeks I had been trying to get my blitz rating back up. I was 1500 blitz and had fallen to around 1320. This has been going on for a while, and I chalked it up to getting older. Then, chess.com dangled a 50% off summer sale on memberships. I wound up getting a diamond membership for one year. And just like that, within a few days, I was back to 1500. I should pause and say that there wasn't any real difference in my play. I didn't have time to do a bunch of endgame study, or learn new openings. I just played. My only conclusion is that my rating went up due to membership pairings. I noticed a definite difference in pairings from when I was a non member to a member. And frankly, that shouldn't be a factor, but apparently it is.

Non premium memberships apparently do have a smaller member pool.

I've had random jumps in rating happen to me at least twice. The first was a small one from 650 to 700, and the second one was from 800 all the way to around 940. I seem to be experiencing a third one as well, though I'm not confident that I'll be able to ride it all the way to 1100.

How is the pool supposedly different? This seems like a conspiracy theory?

Hi

Will you cancel your membership now?