Even with a few wp blog you can get suspended if wp is poorly implemented. Some tips to make your wp install more stable.
1. above mentioned super cache plugin. Wordpress super cache plugin is an extensive modification of the WP-Cache plugin. The wordpress super cache plugin serializes your posts to a
file on disk and later spits them back. It also knows how to update itself when comments are received, etc, so your site is always the most up to date. Note: to use this plugin you must have Mod_Rewrite enabled. Add the following to your .htaccess file: Options +FollowSymLinks RewriteEngine On
2. WP Built-in object cache - The default installation of wordpress can be used to cache database queries. Less database queries = less resources being used . Just add the following line to your
wp-config.php file: // Enable the WordPress Object Cache: define(ENABLE_CACHE, true);
3. Review your plugins - You should go though the plugins you have installed and see if there is a way to make them faster. Any way in which you can make them stop creating database queries and use flat files, or even better, cache
things will help out greatly. If you find that a particurelar plugin is slowing down your wordpress install you should uninstall the plugin or consult the author.
4. If you are doing media-rich applications and serving large files you may want to consider hosting on a vps or dedicated server.
5. keep your wordpress install up to date.
I got these advises from my hosting.I thought I share them.