We at Origo started using Jira about 10 years ago for the tracking of IT trouble tickets as well as to help build excellent software. Today, there are over 1.700 projects in our Jira instance and over 1.2 million tickets. Each customer that has a contract with Origo gets its own Jira Project. Then we adopted SugarCRM just over 4 years ago for our sales opportunities and CRM needs. Both systems are still running today.
SAP is the MDM owner of our Accounts information. So, we do a SAP -> Sugar sync every 10 minutes to keep our Accounts up-to-date in Sugar. Since we already have a field in SAP with the Jira Project key of each of these contract customers (done way before Sugar was implemented), it was very easy to build a custom field of type URL that auto generates the path to the Jira Project of the customer. We decided to create a new tab with the Jira and Confluence links in our Account record view and that is where thise URL fields reside:
So now, our sales reps (and everyone else that uses Sugar) can have a direct link to the customers trouble ticket information in Jira providing them with more information regarding the customer. We also manage couple of different lifecycles in Jira and have done similar links for those.