If you don't own any Koin, you may still want to interact with the blockchain (eventually, this will probably describe the majority of blockchain users--think about how many people use Google without owning any stock in the company).
But no Koin = no mana, so how do I get started? Enter mana delegation. Any other user (or pool of users) can delegate (read: give away) their mana to other users.
But why would someone give away their mana? Probably to help a friend, but the community can also create smart contracts where mana delegation is pooled for specific purposes (like to make a profit through fees or as charity for a specific purpose).
Any fees that the community charges for mana are going to be less than the cost of Koin (have to be competitive). The important part is that the platform doesn't control those fees--it will be a free market.
The other way to interact with the blockchain without Koin is called "receiver pays mana".
We'll go over that tomorrow,
P.S. Check out episode 1 of The Koin Press Podcast wherever you listen to podcasts. This week, I interviewed Andrew Lavine, CEO of the Koinos Group!