WordPress, everyone is talking about it.
This great piece of free software is very flexible, but its not a case of just install and hope for the best.
Most clients want something bespoke in some way, shape, form. This is where plugins are useful, but making the right decision on plugins can be tricky, check the compatible software options, make sure support is good.
Lots of people assume that its just a case of install WP and the plugin and the theme and off they go.
Its never that easy. What will take you possibly weeks to install and configure will take me hours.
I have a wide knowledge of a lot of plugins that are used often in basic installs. I also know how to make these plugins talk to each other, this is very important, communication is everything for a smooth running website. Too many plugins can cause conflict especially when updating and maintaining your site.
I could go on but this is a few reasons why a developer is worth their weight in gold.