Put it this way. Let's say you build this job board of yours. You are just scraping the web and copying job offers into your website to gain content. What if your site gets hacked? Well, no big deal... All you got in your site was pure public data no one cares about. So, having an LLC or not wouldn't make a difference.

Now, imagine your website allows companies to register themselves and post job offers. Perhaps you even allows then to pay for posting job offers. What if you site gets hacked? Data leaks? You may get sued. LLC may come in handy.