Most Round Robins you must sign up by a certain date and be committed to.
Some may be a single card or a group of cards (based on the number of participants) that are completed. You are required to add one thing to the card then pass it on to the next person.
This can be like a one on one swap but it is a serious committed group effort.
A list is created of participants by the hostess, usually a few people 4-6, and the hostess mails to the first person on the list.
Each person adds something, one thing, to the card (or the card group), a stamp, embellishments, phrases, ribbon, whatever you think the card needs to enhance it. After the stamper fin shes, she mails to the next person on the list who does the same.
Usually masks are sent with the card in case people add stamped elements to it and need to mask the images that are already there.
When the card is completed, it is mailed back to the hostess and is posted on the web for all to see the final result.
If it was a group of cards making the rounds, each person receives a product result.
One magazine does this and you can check out the results here.
Cost to you: the stamp and envelope to mail to the next swapper, or maybe a new stamp to add to the theme of the card if you don’t already have it.
If it is a group of cards, an envelope and return postage so you get one back.
In some RRs, there are several groups going at once, sometimes it is all the same card (or set) and sometimes it is a different card (or set). All of this is up to the hostess.
Problems in this sort of swap is when someone breaks the chain or the mail gets lost which are both disappointing.
Round Robins could be considered one on one swapping.
Other considered forms of RRs are UM swaps, TTT swaps, some Mingles.