I'm not sure how that would help. If I opt-out of data collection, I don't think I'd be particularly pleased if I get randomly selected to be one of the users in this "random sample" and the stats get sent anyway.

And if I opt-in to data collection, why would it matter to me whether the stats I'm sending are a result of me being selected as part of a random sample or not? Might as well just _always_ send those stats; it doesn't matter to me.