Can you actually get similar results to paying for promotion just by having really engaging, viral content? My understanding was that this doesn't work so well

Can you actually get similar results to paying for promotion just by having really engaging, viral content? My understanding was that this doesn't work so well anymore. I think paid promotion should be a way of boosting the visibility of content, but definitely not at the expense of content that would have spread virally if it wasn't artificially limited.