Nurture Track Members

One option is to sync leads into SFDC Campaigns.  Other ideas include sending alerts/writing interesting moments when one of their contacts enters into a nurture or moves streams.

I believe the textbook way, at least with the old Traffic Cop implementation, was to create a field on the Contact/Lead objects for "Nurture Track" - you can then run a report off of this field in SFDC. For each nurture track, be sure to add a "Change Data Value" flow step to toggle this field.

New school way might be to create an Engagement Program which syncs to a SFDC Campaign. You can even go a level deeper and create different campaign member statuses and progression flows if your sales team needs details. The campaign object can be a related list on the Contact object, which'll show nurture track status to your sales team.

You can use both methods in conjunction for best results.

I have a field "Nurture Program". This shows the current nurture program a lead is in (I have chosen that a lead can only be in 1 program at a time). I could create SFDC campaigns as well, but I would have to filter out marketing nurture leads (not MQL yet), as these should not be in Salesforce yet. Syncing a Marketo program to Salesforce will result in every member to be synced to Salesforce automatically.

Diederik, the field method should work fine on its own.

True, you'd need to sync all leads over in order to use SFDC campaigns properly, but you could partition which leads go to sales and which don't by using Salesforce record types. 

We utilize SFDC campaigns. Every nurture campaign has a corresponding SFDC campaign. Anyone in SFDC in that nurture campaign is tagged with that SFDC campaign. If someone syncs to SFDC later on we have a back end workflow that will add tha appropiate SFDC campaigns to their history.