Superlatives used in advertising, that it is presumed the public know to be unverifiable or of dubious accuracy, for example “the greatest,” the “world’s best.” Ordinary commercial puffery is usually not open to legal challenge, however where it crosses the line into asserting specific verifiable facts (e.g., “best on-time performance”) it usually becomes legally dubious if not illegal and sanctionable under unfair competition laws or consumer protection statutes.