MTU (Monthly Tracked Users) Usage

RudderStack’s MTU (Monthly Tracked Users) pricing model does billing based on the count of unique users who interact with RudderStack’s Event Stream pipelines within a given month.

The MTU model is an alternative to the events-based pricing model and helps you align costs more closely with the actual user engagement.

Definitions

What is an MTU?

An MTU is a unique user who interacts with a customer’s application within a month and is identified through events tracked by RudderStack.

See the Use case section for more information on how RudderStack tracks MTUs.

How RudderStack calculates MTUs

RudderStack counts unique users by leveraging HyperLogLog that tracks both user IDs and anonymous IDs across various events.

The different phases involved in this process are listed below:

Event tracking

RudderStack tracks events (like identify, track, group) generated by users that interact with a customer’s application (website, mobile apps, etc.)

Identification and association

RudderStack then tracks the following identifiers depending on whether the interacting user has logged in or signed up. See Definitions for more details on these identifiers:

• Anonymous ID
• User ID
• Merged ID

ID pool generation

RudderStack forms the below ID pools based on the tracked identifiers:

RudderStack then computes the MTU count using the below formula:

Note the following:

• RudderStack counts MTUs across different Event Stream sources present in the same workspace. Users interacting with sources present in different workspaces are tracked separately.
• RudderStack does not store any ID for tracking purposes. Also, it does not use your warehouse to obtain or store the tracking information. As a result, note that the estimated MTU count includes an error margin of approximately 1%.
• RudderStack does not track MTUs for the Reverse ETL and Extract pipelines. Support for tracking MTUs for Profiles is coming soon.

Use case

The following use case highlights how RudderStack tracks MTUs across different sources:

• A user visits a web application instrumented with RudderStack’s JavaScript SDK without signing up or logging in. An event is generated including a new anonymousId - RudderStack tracks it as a part of the MTUs.
• Later, the same user signs up to the application and a new user ID is generated for them. A new identify event is generated including both the userId and anonymousId. RudderStack still counts this as one MTU as it tracked and observed the anonymousId before.
• Now, the same user interacts (without logging in) with the customer’s iOS application that is instrumented with RudderStack’s iOS (Obj-C) SDK. This generates an event with a different anonymousId and RudderStack tracks them as a separate MTU.
• Once the user logs in, a new identify event is generated and tracked with the above userId and the new iOS anonymousId, so RudderStack stops tracking this anonymousId and counts them as the same MTU.

The attributed user counts are not mutually exclusive - users can exist across multiple sources.

Get usage details

In your RudderStack dashboard, go to Settings > Organization and click the Usage tab to get the detailed MTU metrics.

The MTU counter resets at the last day of every month (midnight in UTC time).

By default, you see the metrics for all the workspaces within your organization.

Select a particular workspace from the dropdown to get the workspace level MTU metrics.

As seen in the above image, the graph gives the top five Event Stream sources with the most user volumes. Hover over a bar to get the following details:

• Source name
• MTU count
• Percentage of total MTU
• Workspace name

Click the View Breakdown option to see the MTU breakdown by source for the particular month.