There is nothing more frustrating to a blogger then investing a year or two into a new blog and seeing little to nothing in return for all that hard work. At some point, you have to face the what the numbers are telling you.
If you had a business where you were paying $4000 a month in rent and $10,000 to three employees, you would quickly abandon that business if it were only making you $50 a month. The financial costs associated with a blog are really low, and this leads bloggers to sticking with their blog niche for up to 5 years, when they should be moving on after 12 months.