Where free dating sites stands or falls is how anonymous you actually stay in practice.
I logged into the service at different times of day to get a read on how much of it is usable without a card.
What I would look at, in order, for free dating sites:
- How much of free dating sites is visible before it asks you to register
- How many free dating sites profiles show a recent login rather than a join date
- Whether the free dating sites photos survive a reverse image search