A website is a living, breathing thing. It's constantly exposed to the harsh elements of the web. If you try to take the set it and forget it approach, you will without a doubt fail - big time. Staying on top of routine maintenance is a must, but taking a broader look and doing a complete revamp every 2 years or so is recommended.
Now, this isn't a rant. Rather, a success story.
We launched Belles and Lace roughly 2 years ago and we just finished redesigning and performing some major updates on their site.
Now, check the sticker in your car to see if it's oil change time - and revisit your site to see if it needs a tune up.