Think of this as Volume 17, Number 30 of the newsletter I have written weekly since March, 1997. Enjoy.
The difference between a journalist and a blogger is a paycheck.
What I was taught at Northwestern's Medill School of Journalism, back in 1977, was that “a journalist is someone who works for someone who buys ink by the barrel.” That was later updated to “a journalist is someone who works for someone who buys bandwidth by the gigabit.” Although the last should be amended, since most web sites are not journalistic enterprises.
The key phrase above is “works for someone.” A journalist is someone who works for someone. They're an employee. They get a pay check, maybe benefits and a retirement plan. They are subject to ethics imposed by their employer. The employer can pull their press card at any time. The journalist, in other words, is under the publisher's control. And the publisher is subject to business ethics, not journalistic ones.