You can use Munchkin on any page you like, but the thing to remember if you have multiple products or divisions in your company is that Munchkin cannot automatically track a lead across domains. This only applies to top level domains though, not sub-domains. So, a lead could be tracked through
but couldn't automatically be tracked through
So how does munchkin keep track of your leads?
When a lead visits any munchkin tracked page on a domain they've never visited, the system will cookie their browser and create an anonymous lead record in your database. This allows Marketo to begin gathering and saving information about the lead and their activities even before you know who they are. It also allows you to begin scoring the lead record, or running them through any other campaigns you might be using to evaluate leads. Keep in mind that anonymous leads cannot go through all flow steps though(Send Email for instance), and they cannot be made members or a program. You can see messages about this in the results of any campaign where anonymous leads have qualified for the smart list but couldn't be processed through some steps.
Tracking anonymous leads is a bit like having someone come into your store and look around without really saying or buying anything. For this reason, it's a good idea to give them a way to tell you who they are. The main way of course, is by giving them a form they can fill out, which will then convert their anonymous lead record into a known lead record. Now you can really start to market to them, and you have all of their past activities to see what they've been up to!
Next we'll look at how a lead is tracked if they go to one of your other munchkin tracked pages on another domain.
If our lead from above visits another domain that is being tracked with your munchkin code, the munchkin there will track the lead as anonymous to begin with. The same process applies to this new anonymous record. All activity will be recorded, and it can still be scored and acted upon by some flow steps.
If the lead identifies themselves on the new domain by filling out a form using the same email address they previously used on the original domain, then munchkin is able to merge the anonymous record with the original record. But wait! There's another way!
Leads can also identify themselves on a new domain by clicking links to that domain in emails that you've sent from Marketo. Each link in your email is wrapped with tracking information specific to the lead the email is sent to, so you can use Marketo to send out invites for known leads to your new store(domain). By doing this you're saying, "Hey, we know you from our first store, now come visit our new store and let us get to know you there too." As with the form fill-out, once they click the tracked link Marketo can merge the known and anonymous records and begin tracking the lead's activities in both domains under a single record in Marketo.
This same process would need to happen for every domain you're using your Munchkin on, in order to track each lead in all domains under a single record. What we usually recommend is a tagging campaign for each of your domains where you send email(s) from Marketo with a link for each domain. You'd also want to have a form on each domain that leads could fill out.