I don’t care at all.
One postcard or three, the main point is, that I got postcards.
Since late march / early april this year, I don’t get post on mondays anymore. But all the years before. (Yeah, I know the reason, but it makes none sense because I did post/promotion before in piles)
For that reason I got three postcards at a time the other day. That was cool. ^^ I don’t do Postcrossing very often, so every time I open my mailbox is like “Is there a postcard inside?”
Three or five is okay, but when getting a pack of eight or ten postcards, it takes a bit of time to read them all and reply appropriately in the registration message, so I prefer getting not more than five at one time.
The last half year I have been on an exchange semester in Lithuania, where all my incoming mail was processed by a receptionist. I didn’t want to bother her with many postcards so I set my account to inactive but I did keep sending out postcards from Lithuania. This meant that by the time I went back home to the Netherlands, I had a deficit of around 60 postcards that I was due to get. Last month I put my account back to active and all the cards started to be sent to me all at once. At one day I received 20 postcards on one day. Although it was very thrilling to receive so much at once, and because of the large portion there were some non-standard countries in the bunch as well, it quickly felt like I couldn’t give every sender the attention that I would like to, as it would mean that I’d spend the whole day registering the cards. In the end I did of course try to type an extensive message for everyone, as I also didn’t want to postpone registering cards - I prefer doing this the day that a card arrives like many people. (I also appreciate it when my cards are registered the day they arrive)
It was a nice experience to receive a lot of cards a day for a few weeks (I received cards every day for two weeks straight, after that the flow stabilised) but I prefer a normal pace where I can spend more time on the thank you message for each and every postcard. 
i’ve been postcrossing a long time and i can send a lot of cards
when i know i will be travelling or crazy busy, i will set my account as inactive
a few years ago we had lots of illness and 2 deaths in 2 months in our family. i was inactive for quite some time, but i kept sending cards - when i returned my account to active i got 400 cards in one month - it didn’t quite work out as 20 per day, one day i recall had close to 100 - that month was not so enjoyable
this year i have also been inactive for much of the year - to minimise that big dump of cards i opened my account for 2 days in april and received a lot of cards
at the end of july i went back to active again and yesterday there were 90 official cards to register - the link to my story with pictures is below…
i also like to send personalised messages to senders - but sometimes time is just so short, i had to work with a shortcut
i also prefer just a few cards a day, tho sometimes i get a week’s worth as i’m away and cannot get to the postoffice every day
Wow, before I read the previous comments I did not think of the term “bundle” as 40, 50, even 100 postcards at once 
I guess it can get stressful when you’re coming back from weeks or even months of inactive status but kept sending cards regularly. If I’m ever in that situation I will try the tips to just go active for a few minutes or half an hour at a time, to try to spread out the times my address is given out…
Regarding my preference I’m a bit torn if I would rather have one a day, or a few every few days. I notice that I’m a bit disappointed if I open my mailbox and there is no postcard, but on the other hand I really enjoy if I find 3 or 4 cards at once, it feels a bit like christmas every time 
Somehow postcards that are delivered to me seem to get bundled somewhere along the way anyways though. Mail gets delivered every day here from Mo-Fr, but I noticed that I very rarely receive just a single postcard. They usually come in small batches. This seems a bit too weird to just be a coincidence, even if the cards come from different countries with different travel times. I suspect it has something to do with the sorting process of foreign mail in the post center, but I don’t really know 
I prefer receiving one every day. But they tend to arrive in pairs or three at a time.
I prefer to receive it regularly after a long day work 
I’ve been inactive for a while and almost have a difference of 100 between sent and received, so I know it will come in a bundle when I turn back into active. However, normally I would love to get 2 or 3 cards a day, but honestly, I’ll be happy with just one a day.
I prefer one per day, because it wud be a surprise everyday…
I rent a private postal box at the post office and I only pick up my mail every Saturdays, I always end up with a bunch of postcards and some other personal mail