Search engine traffic is essential for growth of any blog , but whats more important is what you do with your traffic.There are plenty of free tools available to track your traffic and the one I use and the mostly used one is Google Analytics. As I said there are plenty more and its up to you to find the one that suits you best.The important thing is to find out which search terms are bringing you traffic and find ways to convert them to regular readers of your blog. With millions of blogs out there this is no easy task but with a little effort it is not that difficult to achieve.
Once you identify the posts which are bringing you traffic its time to optimize them so the readers keep coming back for.Below are few methods that I follow,

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For Wordpress users there are plenty of plug-ins that provide this functionality , and for blogger users adding a few links at the end of the post isn't that hard.Even if you use a plug-in it is worthwhile checking out if they are really related to post.This method increase your page views , average time on site and best of all provide relevant information to the reader.One sure way of getting readers

If the content is outdated add a update
If people are coming to your blog through search engines it is very important to provide them with the up to date information.Adding a update section at the end is the best way to go about it.For new visitors this is a positive sign , it shows that you are up to date on the current topics and you follow up on your work.For example if your post is about selling text links you can mention about the recent crack down by Google.If your post is about comparing Wordpress vs Blogger you can mention the recent future time stamp option introduced by Blogger.

Show off your most popular articles

Again there are plenty of plug-ins in Wordpress to do this.I don't think there's anything like that in Blogger.For a post to get popular it generally needs to be good and directing your new visitor to the best articles is logical.

Recommend a related Affiliate product

All the above methods are great but it want make you any money right ? So if you are getting a decent traffic for some post be sure to recommend a related product that is beneficial to the user.With thousands of business owners out there who are looking for affiliates you are sure to find a product related to your post.And if the visitor liked your product you might be looking at loyal reader.