SaaS companies usually begin with a few lead generation programs such as Google Adwords, radio/TV ads. Typically these types of leads tend to saturate over time, and produce less leads for more dollars invested. SaaS based companies consequently need to be continually searching for new lead sources that they can layer on top of the old ones to continue to grow.
Inbound marketing will take time and effort to increase, but will lead to lower Costs to Acquire a Customer (CAC) and greater scaling than other techniques.
It is critical to calculate the cost of your current marketing campaign and the value it generates to determine the Return on Investment of the current strategy.
Use the "SEM Vs SEO" sheet of the workbook to help calculate this.
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