Why it doesn't work:
Unpredictable and lead quality can be BAD.
Why it doesn't work:
Humans have only so much energy and time. If only humans do your follow-up you'll be capped in terms of maximizing revenue.
Why it doesn't work:
You're competing with other companies over low quality leads and many of the customers are just price hunting
Why it doesn't work:
78% of customers go with the first company that contacts them. By the time you do, they're already sign with a competitor