Getting to many links all at the same time can harm rather than help you in the search engines, not only does it not look natural to Google to have a ton of new links suddenly appear to a site that the month before was not getting any links or whose link acquisition has been steady for a period.

There can be legitimate reasons for a sudden increase in links such as the launch of a new site or new product or something that has been picked up by the news media or bloggers sphere that has been discussed a lot and commented on.

This needs to be taken advantage of and the link spike needs to be continued so that the level of links coming into the site remains high but the spike flattens off.

If this is done properly with links pointing deep into the site the number of pages that Google will list in the index for your site will increase and not drop as pages fall out of the Google listings.

The more pages you have in the listings the more chances you have of ranking well for a variety of key words related to your business and there for the more chances you have of  attracting visitors to your site.

You may all ready know that in search engine optimisation and on-line marketing one of the most important things is to to have links pointing back to your site.

These are seen as votes by the search engines and one website should only link to another if the information on that website is going to be of interest or value to the visitor.

As a website owner you want to promote your website and get it found in the search engines so you need to make other website owners aware that you have great content on your site that their visitors will find useful.

So you now have the whole internet to choose from to get links from, the problem is that there are so many websites and you just do not have time to contact them all and tell them about your site, so reducing the number of sites you need to talk to is vital.

The first thing to do is look at relevancy, you can dismiss large numbers of sites as not relevant to the topic you are discussing, the next is quality, would you recommend this site to a friend of yours? If not do not get a link from them.

The links that are going to be of most value when you are working on your search engine optimisation strategy plan are the ones you find relevant and from sites that you would recommend to others.

Asking if directories and link exchanges a waste of time for search engine optimisation is quite a big question, not all directories are created equal, DMOZ and Yahoo are two excellent directories and getting into either of them should defiantly help your positions in the search engines, however there are also a large number of directories that are not worth looking at.

Link building for Search Engine Optimisation (SEO) is more about the quality of your links than the quantity, it is easy to build links back to a website by trading them with other site owners and filling out directory listings, but you need to consider where is the value in this.

The main search engines employ very sophisticated software to calculate the importance of links, the relevance how difficult it was for you to get it. If link does not have a lot of relevance, is of low importance and was easy to get then you get a low value score for that link, if however the link is very relevant, has importance and was difficult to get then that link receives a higher score.

In a perfect world all your links would be of excellent quality and you would get a great SEO score from the search engines, but you do not get this in the real world and so you need to aim for as high a score as you can get but at the same time not get too obsessed with just the quality.

So a link from a relevant directory may be more valuable to you than one from a site that has no relevancy, the same is true for a traded link, so long as not all your links are swapped or traded and you have some quality along side the relevant but lower scoring links that is a good combination.

So as not all directories are created equal so not all links are equal either.