Some metrics make you feel good (or bad) but are not meaningful, these are called vanity metrics.

These metrics can become harmful.

Reference

Ries, Eric. The Lean Startup: How Today’s Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses. 1st ed, Crown Business, 2011.

Highlights or timestamps

The Lean Startup

many startups give in to the temptation of using vanity metrics, flattering but useless or even harmful metrics that make a company look good but don’t help bring it closer to its goals.

— ^ecf005 from The Lean Startup

Other vanity metrics could be the hours of work you’ve already put into a product or the number of milestones you’ve accomplished.

— ^2effa6 from The Lean Startup