I keep going round in circles on the best 100 free dating websites and I'd rather ask than guess. The viruses case is instructive — the deciding factor is the churn on new sign-ups, with the usual caveats. Every time viruses sites comes up, the honest advice is to keep a note of what you actually spent, based on a fairly small sample.
Loaded sites is where I would start, since it is worth checking how far the free tier gets you before you look at the price tag. Applied to viruses loaded, what decides it is the number of live users, not the price tag.
You get further if you set the radius tighter than feels natural, which is the whole problem with viruses. The reason the best 100 free dating websites keeps coming up is simple: how far the free tier gets you moves the needle further than the length of the feature list, going by the last year or so. What am I missing on viruses loaded?