When you don't have the time to freshen your content yourself, it is well worth your investment to hire a ghostwriter to do it for you. Not only will your visitors appreciate fresh new information, the search engines LOVE sites that are content-rich and change frequently.
If your website is a little tired and could use a perk-up, consider ghostwriting services - you may be surprised over time how page rank improves, and your visitors will come back time and time again to see what great new information or ideas you have to offer!