Discrepancy in number of sent postcards?

[Gypsypost]

I write all cards sent and received into separate books and my numbers have never agreed with Postcrossing - why is this?
Postcrossing lists me down as Sent 290 and Received 284
BUT my actual numbers are: Sent 324 and Received 284 - does this mean that I have 34 Expired cards???

[Kanerva]

“Sent” cards are cards that have been both sent and registered . Do you have any cards that are still travelling? If not, then those cards have unfortunately expired. Cards that are still travelling are not included in the number of sent ones. Cards can still be registered after they have been expired (up to one year). Mail has been affected by the current situation, so it may be that some of your cards are travelling slower these days.