Believe it or not, for "selling software":
Selling Microsoft - https://www.amazon.com/Selling-Microsoft-Secrets-Successful-...
The fundamentals of software sales haven't changed much since this. While B2C SaaS is different, the B2B platform world is still much as described in this book, and more importantly, the buyers are still the people who were buying when this book was published.
While selling today should have changed, many of the enterprise procurement processes that were being set up as this was published are still the same. That makes this an excellent foundation for understanding how to change it up.
That said, you said building an agency ... so do you mean selling software, or selling the ability to deliver solutions that a company can't get off the shelf?
That's quite different.
Selling Microsoft - https://www.amazon.com/Selling-Microsoft-Secrets-Successful-...
The fundamentals of software sales haven't changed much since this. While B2C SaaS is different, the B2B platform world is still much as described in this book, and more importantly, the buyers are still the people who were buying when this book was published.
While selling today should have changed, many of the enterprise procurement processes that were being set up as this was published are still the same. That makes this an excellent foundation for understanding how to change it up.
That said, you said building an agency ... so do you mean selling software, or selling the ability to deliver solutions that a company can't get off the shelf?
That's quite different.