When NOT to choose SQL Server to store your data
You really don't always need a high performing relational database.
Ask if you're making the right choice:
When you don't actually need a database
When you're not using structured data
When you want pure analytics, or something other than a workload involving OLTP
When you need to write to multiple nodes for a single database
When your team wants a PAAS solution (lil pedantic on this, the hosted versions are slightly different)
When your team needs a cheap solution
What do you think?