One doesn't need to know that hundreds of people have been influenced to know that Eliezer's writings have had x-risk reduction value; if he's succeeded in getting a handful of people seriously interested in x-risk reduction relative to the counterfactual his work is of high value. Based on my conversations with those who have been so influenced, this last point seems plausible to me. But I agree that the importance of the sequences for x-risk reduction has been overplayed.