If you want to get ahead in internet marketing, or even blogging, a basic knowledge of SEO is very much required. It is however important not to jump into an SEO campaign before you understand a few things.
In particular, you need to be able to differentiate between the SEO techniques that can help your site and those that can actually do it harm. Backlinks are obviously important but only when done correctly.
When done incorrectly, you can easily find your site losing ground rather than gaining it. Google doesn’t like search engine manipulation and the penalties are severe. Here are eight types of backlinks that are more likely to harm your site than help it.

Sites with lots of Spam

High PR blogs with comment sections that aren’t moderated might sound like a great place to build backlinks but unfortunately they are almost always targeted by spammers. And when you build backlinks on such blogs, you end up looking like a spammer too.
Blog commenting is an effective SEO technique but it needs to be done with care. Focus exclusively on high quality blogs whose comment sections are carefully moderated.

“Bad” Sites

Google isn’t a fan of porn, gambling or online pharmacies. Under no circumstances should you build backlinks on sites that cover such topics.

Foreign Language Sites

Regardless of the PR of a particular site, if it’s written in a language other than English, building backlinks on it is an easy way to attract Google’s wrath. Such backlinks are obviously not natural and are always going to attract negative attention.

Blog Networks

In the past, blog networks were an effective tool for building high quality backlinks fast. Nowadays however, Google is very much onto the strategy and has declared war on such networks.
Buildmyrank.com is now long gone and though there are a few blog networks still in operation, it won’t be long before they follow suit. Such networks are therefore no longer worth your time or money.

Automation Tools

The fastest way to build hundreds of backlinks to your site is of course to use automation software. There are many different tools available that can allow you to build a thousand backlinks with the click of a mouse.
Unfortunately however, Google is getting better and better at spotting the use of such tools. And when spotted, the result is almost always a swift penalty. Focus on quality over quantity. Always build your backlinks manually.

Companies That Use Automation Tools

Whenever you come across a company selling backlinks at ridiculously low prices, you can rest assured that automation tools are being used to build them. Avoid such companies like the plague.

Identical Anchor Text

Regardless of where you build backlinks, anchor text variation is very much required. When you build a hundred backlinks with identical anchor text, it becomes pretty obvious that you built them all yourself.
It’s okay to use the same keywords but you need to change how you use them. Otherwise the bots are going to catch onto what you are doing almost immediately.

Too Many, Too Fast

Finally, there is the small matter of the speed at which you build backlinks. Regardless of the type of backlinks in question, if you build too many, too fast, you run the risk of being penalised. Ambition is important when it comes to making a profit online but keep your backlinking goals modest for the first few months.

Source : Build Backlinks