As a service provider, we have lots of suppliers and vendors working.
Through all those past years’ experiences seen many of them come and go. Some of those who stayed to date show all the listed things.

How to select your vendor/supplier?
1) provides the best trade discount
2) knows his products/services well.
3) you want them to grow.
4) willing to work long term
5) after-sales service.
6) saves your ass if something goes wrong, stands up for you