Marketo: Whats the best way to run a recurring survey?

When you say 'purchase', I am assuming you mean a purchase made on your website or some other 'online' system. I am not assuming a physical purchase made at a store. There are a couple of moving parts that you will need for this... First, your online E-Commerce system where the 'purchase' happens should be added some business logic to send the 'purchase information' to Marketo. It can be done using Marketo API call or even a behind the scene HTTP Post request to a Marketo form. The API call can be to create / update a lead with purchase related information and also potentially add to a list or so. Then in Marketo, you can create a smart campaign that will listen to new 'purchases' submitted by your E-Commerce system. Ie. Listen to new leads added to the list, and send out an email inviting the person to take a CSAT survey. (You can tweak this for repeated purchases, but I am not going in to specifics here) The CSAT survey itself can be created in Marketo or any other solution you might be using... Hope this helps. Please feel free to reach out if you have any questions. Rajesh Talele