Imagine a woman could get a job on her own merits...
She did. It was tennis.
What boards aren't looking to hire top tennis athletes in this day and age?
I think it's more the other way around. How did SurveyMonkey convince Serena Williams to be on their board? Her husband may well have played a role. (Sure, it's not a huge time commitment, but it's not zero either, and I would imagine she has plenty of other organizations and people competing for her attention.)
Reddit probably needs some way to process all the personal information they have gathered over the years into something they can sell. Survey monkey can probably do that maybe?