If a customer lands onto your website using a link of an ad-campaign and left your website after few clicks. After 1 or 2 weeks time he/she comes back from search or direct or affiliate link and place an order with your website then those conversions called assisted conversion. These metrics will greatly help the marketers to understand search marketing response and value created by paid campaigns. Cookie length matter with these conversions - generally if the buying cycle is 2 months adjust the cookie length accordingly so that google analytics give you more insights of the customer behaviour and click source.
Digital Marketing, Analytics and Project Management.