It is Free
Its open source and thus the platform itself is free to use and develop on – starting on WordPress is like less than half the cost of custom developing from scratch or using any other robust CMS.
Additional Functionality via plugins
WordPress community is vast and growing every passing day. Community contribute in the form of plugins which gives you additional functionality at ease and most of them are free or really low cost. Try to only use plugins which are regularly updated as it means the developer is active and it was not just a onetime thing.
In comparison to any other robust Content Management Systems available, WordPress programming is really simple and very documented which makes it easy and simple to start developing on WordPress for even beginners.
Flexible Structure & Template
Because of the flexibility of its structure and code, the framework has no limitations in terms of design customization as other CMS available. You can do anything to it in terms of design.
Easy to Release
All the above factors make the site development really fast and save you a lot of valuable time. You can setup your WordPress on the root folder of your server and run your existing site on live domain and once you are ready with your WordPress website, you can make your site live in seconds by just changing few options in the admin panel.
Themes – multiple prebuilt websites/blogs:
There is a huge bunch of themes available for use – free or low cost. If you are starting with a new website, you can search for themes available on internet and match with your requirements. It is more cost effective in compare to doing a custom theme as you save development cost and as you grow and know your business better then you can start customizing – all depends on your business model. Just make sure that the theme you are selecting is not only just good to look at but has the simple management of the functionality in the backend so you can manage it.
SEO compatible framework:
WordPress system has been built to be search engine friendly. WordPress has the most SEO compatible pretty urls which are most liked by search engines and very easy to manage. Apart from that there are multiple free plugins available for you to extend the SEO functionality and manage it easily all by yourself.
WordPress release latest updates every now and then and you can simply implement that with click of a button. You will need to make sure that any customizations you do are only done in your theme folder. WordPress upgrades update the WordPress core files.
Easy Content Management:
Writing content in the backend is as simple as writing in MS Word. Also, you can play around with the placement of the features and add new features yourself mostly all by yourself – just make sure that the developer utilizes the power of WordPress when working on your site (making the sections widgetized to the extent possible).
WordPress as a Company itself is run by smart innovative people and though it is open source it has a huge funding behind it for them to push developments on the platform itself.