docs: tweak limits (#4304)

docs/docs/system-administration/system-limits.md

@@ -20,14 +20,6 @@ In order to ensure consistent performance, Flagsmith has the following limitatio
 
 - Maximum size of a Segment Rule Value is **1,000 bytes**
 
-### Admin API Rate Limit
-
-Requests made to [Admin API endpoints](/clients/rest#private-admin-api-endpoints) (i.e., non-SDK endpoints) are subject
-to a default rate limit of 500 requests per minute.
-
-If you are self-hosting, you have the flexibility to modify this limit by adjusting the value of the environment
-variable `USER_THROTTLE_RATE`.
-
 ## Overriding Limits
 
 ### SaaS
@@ -38,3 +30,51 @@ Please contact us if you want to override the current system limits.
 
 You can modify the system limits on a per-Project basis. These limits are defined in the database against the Project.
 The easiest way to modify them is with the [Django admin](/deployment/configuration/django-admin.md) interface.
+
+## Traffic Limits
+
+:::info
+
+When we say _rate limit_ in this document we mean to-the-second limits on API usage.
+
+When we say _plan limit_ in this document we mean the month to month usage limit defined as part of your plan.
+
+:::
+
+### SDK Limits
+
+Requests made by our SDKs are _not_ rate limited, by design; we can't predict what sort of profile your traffic will
+look like.
+
+There are scenarios where we will block your API calls, based on the _plan limit_ you are signed up to, which are
+detailed below. You will be notified and given warning in the event that we are going to stop serving your flags on
+account of you going over these _plan limits_.
+
+#### Free Plan Limits
+
+If you are on our Free Plan, we will stop answering requests from our API if you go over your
+[Free Plan limit](https://www.flagsmith.com/pricing). We will send you a warning email 7 days before we block your
+requests, to give you time to upgrade your account.
+
+This block is cleared 30 days after the warning email was first sent, or when you upgrade to a paid plan.
+
+#### Paid Plan Limits
+
+##### If you go over your plan limit by a factor of 2 or less
+
+If you go over your paid plan limit we will email you and give you a 30 day grace period. We will then charge you an
+overage for that calendar month (or the contracted overage rate if specified in your Enterprise agreement). Please refer
+to our [Pricing Page](https://www.flagsmith.com/pricing) for overage pricing.
+
+##### If you go over your plan limit by a factor of more than 2
+
+We will bill you for all overage above your plan in the current calendar month. You will be charged for the overage at
+the end of your billing period.
+
+### Admin API Rate Limit
+
+Requests made to [Admin API endpoints](/clients/rest#private-admin-api-endpoints) (i.e., non-SDK endpoints) are subject
+to a default rate limit of 500 requests per minute.
+
+If you are self-hosting, you have the flexibility to modify this limit by adjusting the value of the environment
+variable `USER_THROTTLE_RATE`.