Have you made a successful blog by just blogging daily without link building and keyword research?

I have a blog that does just that.
Other prominent bloggers link to me to discuss what I write (because they either agree or disagree with me)
I have in-content links from newspaper websites (such as the New York Times; Boston Globe and Vancouver Sun) as they link to my opinions on topics.
etc etc
That is how it is supposed to be. The whole current and future of the Google algorithm is to reward that. Work with it rather than constantly trying to find ways around the algorithm.

How many web 2.0's; article submissions; forum posts etc do you think one of those dofollow in-content links from ONE newspaper site is worth?

I built up a following via facebook, twitter in the industry because they wanted to read what I write; I write something and put it out via facebook and twiiter ... it takes care of itself; its gets liked and retweeted: others eventually write something linking to it.

I think it's silly to expect traffic without some type of self promotion.

I have old download sites that were built well after a full year of posting on a niche forum (not IM). I built a solid rep on the largest niche forum, they even made me a mod (I'm still a mod today). The traffic volume for that niche forum is very similar to Warrior Forum.

Anyways, I posted a boat load of downloadable niche files directly on the niche forum that I don't own, I even took request for downloads (all legal, all created by myself). I had a few thousand post on that niche forum.

My point here is, I did self promotion by helping other people without asking for anything in return (remember, at least a year before I built my first same niche site). Once I built my first site I had at least 1,500 traffic per day from that niche forum & other same niche forums where traffic built links for me without me asking for the links. I even had links being built on forums/blogs/sites that I've never even joined or heard of before researching my link profile.

There's nothing wrong with self promotion, the key is to make the self promotion helpful for targeted traffic & building a solid rep where folks will trust you enough to follow your links, even If they're nofollow links. There's more to life than SEO though I also do SEO but I could get by without ranked pages considering I established myself in the niche. I mingle with people I want on my own sites.

Keep in mind when you help someone else in your niche on a public site, there's dozens of other folks watching that will never post a comment. They will follow a link.

You need to do some kind of promotion because if you want that your blog reaches to bigger audience then you have to promote it on social media and sometime it will be good to do Link building as well.

I agree to disagree, in that self promotion isn't necessary! In fact, keyword research is promotion in itself. However, I consider it to be more SEO than advertisement. My point being, that there are other ways to attract traffic to your site/blog by simply "allowing" people the ability to search for it and to find it. Search Engine Optimization, speak mode boss.