I had a really good question about the virtual swaps, and so I wanted to make sure I posted it to make sure everyone read the clarification.
Thank you to Lili, who wanted to know if the fees had to be paid for each round you participate in. The answer is no. The fees are just a one time entry fee for however many rounds you choose to do.
However, if you left the swap and wanted to come back again later (like a few weeks later), you would need to pay the fee again. Essentially, once you get your package of books back, you have left the game.
If anyone else has clarifying questions, please let me know!