Hello Postcrossers -
I have been a user since 2018, and have mailed over 170 postcards.
You can laugh at me, and i’ll take it. Or call me a shame. But I just REALIZED there is such thing as U.S. POSTCARD STAMPS that cost way less than a normal U.S. domestic stamp.
Just wanted to put this out there just in case there are users that don’t want to admit it and didn’t know about this.
Bye!!!
Until I began Post crossing last year , I had not really paid attention to stamps unless I needed to purchase some, and just picked the pretty ones I liked at the local post office. Now I have quite a collection going and yes, really use the postcard stamps and global forever. Its becoming expensive!
Postcard stamps are good though. They’re a bit cheaper overall
They’re great. I usually get an entire roll of 100 at a time to last me a while.
Do note that those postcard specific stamps are only good for the domestic rate, i.e. sending a postcard to an address within the United States. The rate for any first class item (letter or postcard, up to one ounce) sent internationally is $1.20, and you can use any combination of stamps to achieve that (although there is a round stamp specifically for that purpose).
There’s also a size limit for postcard rate. So I was making my own postcards (with the cardboard that comes with stamp sets when I order online – recycling!). And those cardboard bits are above the size for the postcard stamp, so you have to use the regular stamp.
According to USPS.com:
No more than 4-1/4 inches high x 6 inches long x 0.016 inches thick
I’ve been enjoying the fish and the barns for the postcard stamps. Which is your favorite?
I like the seashell postcard stamps for 2016, I still have a few which I use only for cards to myself sister who collects seashells.
You may not be the only one who didn’t know: I just got a nice hurray message from a US Postcrosser letting me know I didn’t need to put a Forever stamp on the postcard I sent. I’m sure I’m not the first Postcrosser they’ve told.
It was a kind thought, to try to save me money on postage — but I’m a big fan of making the stamp match the card, so I use Forevers on domestic all the time… 
I like the new barn stamps better than the fish
I know this is months old, but I JUST NOW learned about postcard stamps and now I feel dumb haha. You realized a lot sooner than I did!
I’ve been using forever stamps on a few postcards because I thought I ran out of postcard stamps. As I cleaned up the office this weekend, I found 2 more sheets of the coral postcard stamps! Guess I had a few after all. But I still have to watch the postcard size. 
You know the best part? That forever postcard stamp - currently all .44 cents of it - can be used to send a postcard to US Territories, too, like:
Basically, you can use the domestic rate for the territories, too, for all other mail FYI.
I have this information clearly posted on my profile but most cards I get from US mainland come with US global stamps(1.40), sometimes a forever and rarely a postcard stamp.
Maybe there should be a separate thread to spread the word among US Postcrossers.
Similar to the thread/poll @paulo did for Canadians:
Special Rate From Canada to US
I’m using a US One Dollar stamp and a postcard stamp on International cards for a total of $1.44 USD.