Almost anything you want to do to your WordPress blog can be done via a plug-in. And plug-ins do things more cleanly and efficiently than a “hack” or inserting third party code yourself about 99.9% of the time.
For instance, if you have a Google Analytics account and want to add that code to your blog, there is a plug-in for that. Why use a plug-in instead of adding the code to the footer.php file as seems only natural? Because not all themes are created equal. Because other plug-ins may be inserting code into your footer.php file and fighting with the code you are trying to insert. Because future plug-ins may interfere with the code, etc.
I’ve experienced Google Analytics code not working, even though the code was installed correctly, due to the peculiarities of a client’s custom WordPress theme (created by someone else). And using the Google Analyticator plug-in was the only way to make the code work in this case.
The amount of WordPress plug-ins is staggering, but that only makes sense. WordPress on its own is absolutely awesome, but is basically an empty canvas. It needs your content. It needs your unique look applied to it. And it needs its extended functionality to be whatever you make it – think of the plug-ins directory at WordPress.org as an a la carte menu – and build your own hot lunch!
Plug-ins designers usually love what they do and spend all their spare time creating and perfecting these plug-ins. So their specialized installation is virtually always going to be cleaner and more efficient than cutting and pasting some code or applying a creative “hack.” A word of warning: One should only ever use plug-ins from the official WordPress Plug-Ins directory. Using some rogue plug-in from a web site somewhere could open you up to security problems, malicious mischief, unwanted links on your site and more. The official WordPress Plug-Ins directory is the only place you should be acquiring your plug-ins.
So what are you waiting for? Give the plug-ins a try! Save yourself some work and enjoy the benefits of using an expertly-created element for your WordPress blog. They’re free and of the highest quality. How can you lose?