We plan on implementing several encryption models. Each model has its own benefits. On one side, we can put cipher text on the URL and point to the standard PGP key servers. This will likely be free (since Privly servers don't need to be involved) but it doesn't give you the benefits of controlling the content host (like changeability, share-ability, and destructibility). Hosting content like Privly's is likely costly since the network demand is similar to Twitter, so we will pass these hosting costs onto the user.
Basic encryption system = free
Advanced encryption and privacy controls = paid