all sizzle and no steak

Noun

 * 1)  A thing or person which fails to measure up to its description or advance promotion.
 * Her latest novel is all sizzle and no steak.
 * 1) * 1999, "Nonprofit community increasing nervousness about Year 2000" by Gary M. Grobman. International Journal of Nonprofit and Voluntary Sector Marketing, vol 4 issue 2.
 * Y2K may be the equivalent of the Kohotek comet—all sizzle and no steak.