Once you write an article and post it into your website, It lost somewhere into your archives after lot of posts. Readers unable to see your older post until you don’t tell them that there is another good article to read in your websites archive.
You can use a simple plugin “Tweet Old Posts (http://wordpress.org/plugins/tweet-old-post/)” to keep your old blog posts alive forever.
It’s not recommended to have a lot of WordPress plugins but you can use this plugin to tweet your older articles on your twitter account periodically. This plugin is very useful on those months when you can’t publish any article but still it will tweet your older articles in a consistent manner.
The main feature of this plugin is that it will randomly select an article from your WordPress blog archives and tweet it out at the timed intervals you set. It’s up to you to set the tweet time.
Here you can set the frequency of tweet to as often as you like. You can also set the plugin to only tweet posts that are (x) number of days old.
Another great feature of this plugin is that you can mark certain posts to not be tweeted on twitter. You can set it by simply go into the plugins Exclude posts page and select the posts that you would want to exclude.
It also provides a feature to short your website URL by so many URL shortener bit.ly, tinyurl etc.
There are many more features are available with this plugin which you can use after installing it in your WordPress blog.
I am using this plugin and found this to be very helpful tool to keep a constant flow of traffic from Twitter on my older posts.
By this way you can keep your old blog posts alive forever.