preface: indicate where to ask for commercial support

Change-Id: I386d9bd31afe363677f23751d9ffe99f14800484
---
M common/chapters/preface.adoc
1 file changed, 14 insertions(+), 0 deletions(-)

diff --git a/common/chapters/preface.adoc b/common/chapters/preface.adoc
index 7dad998..f102aea 100644
--- a/common/chapters/preface.adoc
+++ b/common/chapters/preface.adoc
@@ -300,3 +300,8 @@
 software) provided at osmocom.org is put together by volunteers for
 free.  Treat them like a friend whom you're asking for help, not like a
 supplier from whom you have bought a service.
+
+If you would like to obtain professional/commercial support on Osmocom
+CNI, you can always reach out to sales@sysmocom.de to discuss your
+support needs. Purchasing support from sysmocom helps to cover the
+ongoing maintenance of the Osmocom CNI software stack.

