Close to my view, except on whether people reply or just collect matches.
What decided it for me with that one was whether the recommendations improve with use.
I logged into that one at different times of day to get a read on how much of it is usable without a card.
If you bounced off this before, revisit the app and check how much of the base is genuinely looking first this time.
The measure I would actually check on it is whether people reply or just collect matches.