When buying back links..

If you're looking to mix in diversity with "click here" or "read this" or "this article here" then I would just do that with social bookmarking. If you're going to pay for links, then I'm guessing you're paying for something with trust and authority behind it...I would aim to have those anchor to my site with a proper keyword term.

Diddy, back like buying can be a bit of a minefield. Your right to post to here if you are unsure as many people out there will guarantee you if you buy from the them you will get sky-rocket your traffic and boots you SEO results.

A couple if tips I would have are:

Budget - make sure you know what you are willing to spend and keep to that figure.

Quality over quantity - It is harder to increase page rank the greater it becomes so getting high quality backlinks becomes you friend.

Research Again - an ".edu backlink" is great but if it is from a site with many backlink slots it will be a less effective backlink. Look for websites with limited backlink slots.

Stay Away From Homepages - It is better to have a backlink from a page within a site rather than the homepage.

Mix up your anchor text - These days you need to have varied selections for words to use as anchor text. Yes from "click here", your website url to relevant keyword. Your are trying to make it look more natural.

Try and stay in niche - Look for good sites within your niche and get links from there to.

Anyway there is a lot to backlinking but I hope this helps. I'm sure there are more people out there with better tips but I just wanted to start off.

Oh and make sure you clear on what you get when buying the backlink. Make sure it will stay there and be yours for the long term. If not you might find it has been resold to someone else and you've lost your money a month or two later.

Goodluck