What's more powerful, word-of-mouth or following someone else's lead?

Researchers have published new research that reveals the power of word-of-mouth in social learning, even when compared to the power of following the example of someone we trust or admire. The same research found, however, that both word-of-mouth and following someone else’s lead are two of the most powerful dynamics in influencing others through social learning.
Source: Science Daily, https://www.sciencedaily.com