There are two ways off the top of my head.
1. Trigger on the Sales Data table or tables on insert/update/delete that does the same to the other database.
2. Replication - fairly overkill but more transparent as you will notice failures in data transfer. Although replication is most complex of the two.
This is not the exact solution but I am sure you can do a bit if reading, Concentrate on 1 and 2 if you are interested.
Kind Regards Nick Kemp.