There are wide varieties of SEO tools available on the net, somewhere around thousands of them, but the real question is whether they are useful or not.
Many SEO companies have developed different tools to boost your rankings on the internet. Some of these tools are good but can also be dangerous sometimes. For example, suppose you have a website named http://www.abc.com , and you install automatic link exchange software on your web server. It could be possible that your website's rankings will start to boost, but can also give your website a kiss of death if done unscrupulously.
Many search engines like google, yahoo, and msn consists of complex rules of algorithms. Each and every site in their database is specifically arranged according to their business content. Now suppose, your automated link exchange software changed a link with a company named http://www.xyz.com , and this http://www.xyz.com , was further exchanging link with a site for adults only, it could be possible that your domain is entering a no-entry zone. Sharing your links with these adult websites can put your domain in jeopardy, and can paralyze your domain forever.
Using these automated link exchange software's you can increase your rankings on various search engines, but it is more important to keep an eye on your domain like a hawk watching its prey .
This will not only ensure higher rankings, but also a safe future for your domain. Google, and MSN regularly update their algorithms, and any fluctuation in algorithm can prove to be a minor or major disaster for your domain.
The summary of this whole passage is that no matter how advanced seo tool or software you use, SEO expert intervention is mandatory for any domain to be successful and safe. These software and tools are after all developed by human brains, and since the most powerful SEO tool is your brain.