At some point early this year, the MRC and IAB will announce a standard for in-stream video viewability, defining an ad as "viewable" if it is 50% within view for more than two seconds. It may not be a perfect standard, but it's a good start. Now, every publisher, ad server and vendor has the blueprint to offer an in-stream video viewability measure. There are no more excuses. Yet viewability is still in its infancy, especially when it comes to in-stream video. Now that everyone can begin reporting on viewability, what comes next?