Quality can mean more than one thing. Personally, I like backlinks that also deliver traffic. That means doing the work of finding sites where people who are already interested in your topic might gather. These may potentially delver SEO benefit over time as well. But at least you can get traffic from them too. I had one link in a popular on-topic forum that delivered traffic for years. It is hard to know the true SEO benefit of just one link though.
Yes.. What do you mean with QUALITY... If you could get a backlink from Good websites in YOUR niche, this is a quality backlink. If you could write a quality article and place it on 1st page on Google, then this is a quality backlink too... Also, good web2.0 and Social Bookmarking and Social media backlinks could be quality, if ONLY the websites are NOT spammed to death with many, many and again MANY other websites!
Make content that people actually want to link to (stuff that is interesting, informative, funny or whatever) and market it. People will link because they like it. (As a case study, Matthew Inman and his comics for theoatmeal.com - look at his following on social media, what and how he achieved with raising money for charity, etc). One of those links is worth more than ten million idiot spam ones (web 2.0s, article sites, social bookmarking, blog comment and all the other crappy spam people think is SEO). Yeah, some niches are harder to get off the ground. Try guest blogging. It's not exactly a high value link, but can potentially bring traffic and still better than the aforementioned idiot-spam.
Getting quality backlinks is very important for any website. In order to get these make sure your site get listed in all high PR article sites, Social bookmarking sites. You can also post PDF's, classifieds, blog postings.
I agree with you. The key is to provide killer content that people like; that's the best way to get links from other sites to your site. Content is the key in this business.
link exchange, gust writing, social posting, updating your blog/ website regularly, bookmarking can give you more back links.