Yes bank-links which are used for purposes mentioned in the link are really not advisable, thanks for the information.

A bad backlink is a link that comes from a not-so trusted website. ... Before Google launched the Penguin algorithm, websites were violating Google Webmaster Guidelines with black hat SEO. Essentially, people were paying for links so they would have higher rankings and higher authority—not okay.
1. Avoided from Paid Links Avoid buying/selling Backlinks obtained them naturally. · 2. Link Exchanges Dont try to exchange alot of links google
As per Google "don't try to be natural be natural" so it's better to follow their guideline, if you want to know more about SEO here is a good article http://www.biginternetblog.com/things-to-know-about-seo.