If your employer wanted you to take your relationships with you, they would make your CRM data downloadable. The best sales people find a way to do it anyway. We make it easy with the Bravado Portfolio. Add your clients to your Portfolio so they stay close, no matter where you go. You can even request testimonials to make it easy for them to vouch for you where prospective new customers, as well as future employers can see.
Relationships are king and they will be the #1 factor for successful selling moving forward. In all of the companies I've worked at I sold/talked to different personas, different departments, different everything. It is often considered hurtful to your career progression when you switch industries. All that tribal knowledge, all those relationships..gone. WRONG. I just talked to a former customer from my first job in a completely different industry. The relationship + timely and relevant messaging is why we talked. You never know when a connection, a conversation, or a relationship will circle back around to relevance. Don't discard any of them that you have made along the way.