Referral program: look up referrer with a custom field Hi,I'm creating a referral program with the flow below, and I have a few questions.Our referral program flow (C= customer, L= referred lead):1. C enters L's name, email address etc and C's email address in a form.2. The form creates a new lead record based on L's name, email address etc. C's email address will be stored in a custom field called "referrer's email" (synced with Salesforce).3. Marketo looks up C based on "referrer's email" and stores that C has referred L.We need to have both C and L's information, as we will send different emails to C and L, and later we will reward C and L if L becomes a customer. Questions are:a. how can I lookup C's record based on "referrer's email" tied with L's lead record?b. what's the best practice to collect the data of whom C has referred? Counting up the number of leads C have referred is not enough, as we'd like to communicate with them later. Also, we expect a C might refer several Ls. c. Is there any better way to have a form for this kind