The key factor is that for a lot of bloggers audience is the reason they blog. Audience is the ROI of the time spent blogging. Someone who thinks they've got thousands of visitors may spend more time blogging rather than spending it with their families or working (which they would have done if they only had 10 readers)
It's even worse if you're using it for a company blog (like many startups are doing). Because your blog page view stats can often become part of investor pitches or sales material to show traction. If you write an advert and say 10,000 people read your blog when they don't and that influences your customers buying decision, you can be prosecuted for misleading your customers.
It's even worse if you're using it for a company blog (like many startups are doing). Because your blog page view stats can often become part of investor pitches or sales material to show traction. If you write an advert and say 10,000 people read your blog when they don't and that influences your customers buying decision, you can be prosecuted for misleading your customers.