The "sales funnel" is played out; it's time for a new metaphor. In this presentation, Gainsight CEO Nick Mehta talks about a more appropriate metaphor - the hourglass - that represents accurately the value to the company around both the customer acquisition process, but also the retention and expansion of those customers to grow revenue.
The most successful Enterprise SaaS companies know that growing revenue only through new customer acquisition is the less efficient way to scale. Rather, they understand that growing revenue within your existing customer base - through up-sells, cross-sells, and expanded use - is the most profitable way to scale.
In fact, Enterprise SaaS companies that grow revenue - and company valuation - by expanding revenue within their existing customer base also know the key to making this work is to focus on - and operationalize - Customer Success.