Visual Analysis - Comparing KPI To A Benchmark

What methods do you use to effectively communicate "Here is the KPI versus a Benchmark"? One of my favorite is to use the chart series type to indicate the difference between a realized KPI and the theoretical goal. Here's an example:

To add this line, simply reference it in your select statement as an additional column. Then you can define the series settings on the right hand side of your chart editor to display benchmark as a line while the rest of your data is displayed in bar format.