How do I view the total # of leads on a smart list and view its performance over time?
To see the number of leads in your smart list go to Leads tab, you will see the number of leads in the bottom right corner
You can subscribe to a smart list to monitor its performance Subscribe to a Smart List - Marketo Docs - Product Docs
If you want to see graphs and trends I would rather build a report
In addition to Iryna's points, you can also create snapshots of a smart list at any point in time adding it's members to a static list. You can do this in a daily or weekly batch.
Thank you - Is there any way to view the # of leads that were on the smart list last week or last month or three months ago...or would I have had to done the snapshots, as you describe above?
Depends on the criteria of you smart list. In some case, you can run a filter with a time constraint. But if the smart list is a bit complex, unfortunately, it will be very hard to impossible to get the content of you SL as of 3 months ago. All the more so as some of the activities are archived after 90 days and cannot be queried any longer after that period.
Hence the snapshots. The interest of the static lists is that you can then run a "was added to list" smart list with a time constraint.
If this is really important to you, I suggest using RCE or another snapshot tool like Tableau. Marketo MLM is not ideal for this type of analysis.
Thank you, Gregoire. Follow-up question: How can I add members of the smart list to a static list (I assume this can be set up to be done automatically every week or month or whichever timeframe I chose, right?)
Just create a smart campaign with the following setup:
Every week, this will remove from the list all of it's member and add again to it only the ones that should be there on this very day. When you will use the "was added to List" filter on a specific week, it will give you the exact member list.