Search Engine bots like Google, Ask, AOL, Yahoo, MSN etc, DDL site Bots like MechoDDL, Twilight, NexusDDL and then other warez bots like FileTube, WarezSearch
Then you have bots that check if your site is online like pingdom, gtmetrix, etc.
You have SEO bots that visit your site and track your keywords for those site rating systems.
Then you have browsers that predownload a page like Google Chrome. If your site shows up in search results Google starts to pre download the links you usually click on so when you click on the link the page appears instantly. This is great for Google Chrome users as it really speeds up internet browsing but it adds about 20% extra traffic to your site although this varies from site to site.
If your on wrzc website list that's another bot too.
Their are hundreds of thousands of bots and automated systems running. I know as I've built loads and even released the code as a plugin for some DDL Site Bots here on WJ.
Sure their will be some real users that visit your site that have javascript disabled so your number could be more like 300 but your far better off tracking the Google Analytics viewers as these are real people and you can track where they enter, exit your site and learn how to improve it.