<p>Do you think an average supplementary essay is worse than no supplementary essay at all? I feel confident in my Common App essay, but I fear that I used up most of my good ideas in that one, and my Supp Essay will be more perfunctory.</p>
<p>I don't exactly know, but IMO it could hurt b/c you are giving them something extra to read. By submitting a supplemental essay, you are pretty much saying "This is essential and could not be conveyed elsewhere." If that statement falls short, I could see an AdCom being annoyed/frustrated.</p>