RE: Feeless Transactions Called Into Question: Hive As A Social Media Network

With high level of activity the most probable scenario is that Hive will start routinely hitting block size limit for prolonged periods of time creating backlog of transactions that will start expiring before getting included in the blocks. In such case more HP won't help you since there is no mechanism to prioritize transactions of people with more stake (such mechanism could be individually introduced by some witnesses without breaking rules of consensus, but I doubt anyone with proper knowledge would waste their time on it). Note that such thing already happened in the past, but only because witnesses vote to keep max block size at a minimum, which is 64kB. They can change it at any moment for up to 2MB - a 32 times increase.

With increased block size and constant high activity we would indeed see RC costs going up as resource pools get consumed faster than they refill. Then you would need to increase your HP to be able to afford unchanged level of on chain activity. Even in such scenario you will first see people having problems posting large articles or creating accounts. Transfers are one of the cheapest operations, so Hive would become completely unusable as a social media platform months before RC costs could make transfers prohibitively expensive.

It doesn't mean you could not exhaust your RC mana on transfers alone. I've seen even orca level accounts with so much activity that they are constantly running on fumes, so a free account with no HP can run dry pretty easily even at current costs.