There are so many solutions to membership software out there. That it is just plain confusing, but personally I prefer to use WordPress to hold my membership sites for a variety of reasons. WordPress has many excellent, free themes or designs and almost endless directory of plugins or add-ons to extend the functionality of the blogging software and it is search engine friendly.
A theme is a design for your blog, the great thing about WordPress is that there are literally thousands and thousands of themes that are just sitting there waiting for you to plugin to your blog for free.
Because WordPress separates out things like the users the cost and design, you can pile up your blog with hundreds of articles worth of content and change the entire design of the whole blog with the just a few clicks and keep all of your content, all of your comments, all of your users completely untouched. Many of these themes look fantastic, many of these themes look better than professional looking websites that cost thousands of dollars and they are all for free.
WordPress also has many many many plugins to make writing your post easier, to make your visitors commenting easier, to integrate with social networks and more. No other blogging software on the planet has as many plugins as WordPress that is just a simple fact, that alone should get you to reach WordPress because there is a plugin for everything. A plugin for a calendar, a plugin to charge access to a blog and make it a membership site. A plugin to add your flickr photos, a plugin to show your twitter updates, a plugin to even take your new blog posts and update on your twitter account for you. It solves everything the final reason you should use WordPress to run your membership site. Is that Google loves blogs with most membership site software it is possible to show part of a blog post and protect the rest for paying members.
This way you can get hundreds and hundreds of pages listed in Google and ranked highly because Google ranks blogs more higher than regular web pages, and because it is a blog you spend less time and effort getting the content on your site than the average person, plus there are lots of hidden goodies within WordPress such as the blog and ping concept which means that in the past. People had to wait for their pages to be spidered but when they post to a blog it is listed on Google in a matter of minutes.
Those are the reasons why you should use WordPress to run your very own membership site. The themes the plugins and the search engine advantages, are you interested about membership sites yet?