This is certainly not a complaint. I’m fairly new to Postcrossing and I always assumed you send a card, the recipient registers it and your name is then given to another member, who writes to you. Therefore for each card you post, you get one back.
My sent/received figures were balanced at 24/24 but yesterday a whopping SIX cards arrived simultaneously. I have now received 30 but only 24 registered as sent. Quite an imbalance.
Does the algorithm sometimes permit you to receive “extra” cards? Perhaps there has been an influx of new members and they need addresses to write to? If so, I would have assumed any slack would have been spread throughout the membership.
But like I said - I ain’t complaining.