Ooh, good point! In my mind, 0 is not a number, as, a number is a representation of a quantity and "nothing" is not a quantity. Zero is a placeholder though, useful in numeric representation systems that use columns.
In that case, 0 also represents the "first" value, even though it doesn't amount too much. (Ever hear the trick statement, i know the score before a baseball game starts? It is 0 to 0.) Hence, the poll question is really, what is the first representational digit in base 1, colloquially asked as "what is the first number after 0".