The simple and fair approach to monetizing the API is to have it be a simple "this much for these many calls."
That makes sure that applications are incentivized to write code well that doesn't take advantage of a free resource.
The Apollo push notification part of the server is hitting 600 requests per hour per user - 10 requests per minute per user. That has a cost to it for Reddit even if not a single page is rendered for a mobile app.
It doesn't matter if it's a headless moderation tool or the push notification server or an exceptionally poorly behaving front end. API requests have a cost that up until now have been free.
If Apollo turned off the notification server, he'd be down to pennies per user per day for the app. If it was scaled back to a request every minute it would be $1/day/user. Scale it back to a check every 10 minutes and you're back to pennies per day per user.
As it is, it was designed with a free and nearly unlimited rate limit available.
Trying to do an audit of advertisements being displayed (again, easy to defeat so that the auditor sees the ads while others don't) this doesn't fix the problem that apps are taking advantage of free resources that aren't free to the host.
If the cost of the API is too high for the load that it (and any backend) puts on the host, then it should be up to the app designer to find a way to monetize it - it is their responsibility to write the code within the limits that it can afford.
This seems very backwards to me. The job of business isn't to do the "simple and fair" thing. It's a) to generate maximum value, b) to extract enough cash to pay the bills and then some, and c) work to keep costs at an effective minimum.
The marginal cost of a single API call is approximately zero. Reddit, like most SaaS businesses, is much more about fixed costs than variable costs. I think they are much better off following the standard freemium approach, where they give away what's basically free, and then use value-based pricing to get a fair share of the possible revenues. The sort of cost-based pricing you suggest a) doesn't match their cost model, b) overcharges for valuable things that may not produce direct revenue, and c) undercharges for things that are especially valuable to users.
That makes sure that applications are incentivized to write code well that doesn't take advantage of a free resource.
The Apollo push notification part of the server is hitting 600 requests per hour per user - 10 requests per minute per user. That has a cost to it for Reddit even if not a single page is rendered for a mobile app.
It doesn't matter if it's a headless moderation tool or the push notification server or an exceptionally poorly behaving front end. API requests have a cost that up until now have been free.
If Apollo turned off the notification server, he'd be down to pennies per user per day for the app. If it was scaled back to a request every minute it would be $1/day/user. Scale it back to a check every 10 minutes and you're back to pennies per day per user.
As it is, it was designed with a free and nearly unlimited rate limit available.
Trying to do an audit of advertisements being displayed (again, easy to defeat so that the auditor sees the ads while others don't) this doesn't fix the problem that apps are taking advantage of free resources that aren't free to the host.
If the cost of the API is too high for the load that it (and any backend) puts on the host, then it should be up to the app designer to find a way to monetize it - it is their responsibility to write the code within the limits that it can afford.