CREATE TABLE table_23499946_1 (directed_by VARCHAR, us_viewers__in_millions_ VARCHAR)

How many directed by have 2.80 as u.s. viewers (in millions)?
SELECT COUNT(directed_by) FROM table_23499946_1 WHERE us_viewers__in_millions_ = "2.80"
SELECT COUNT("directed_by") FROM "table_23499946_1" WHERE "2.80" = "us_viewers__in_millions_"