[j2kun]

I meant incentive with respect to career advancement, in the narrow sense of what metrics hiring and tenure committees use to make decisions.

[syllogism]

To get a grad student or post-doc position, you're really just trying to convince a specific human that you're smart, useful, and to some extent personable. Metrics are a good argument for that, but having them know who you are before you apply is even better.

This applies especially if you write the distillation targeted at the lab you want to hire you.