@Ryan Car - Unlike what people have said above, what you can find at county websites varies tremendously by state and by county. Some are great, some are terrible, but none are very efficient at helping you build a marketing list. If you value your time you'll end up using a 3rd party service that collects, collates, cleans, appends, etc the base public records data into something usable.
Ownership and characteristics (beds, baths, etc) are sourced from county assessor offices. Sales, mortgages and foreclosure data is sourced from the county recorder office. Some of us also append other data like demographics (age, gender, etc), phone, email or even social media profiles.
While it certainly doesn't hurt to do SEO and cast your message in a bottle onto the sea of a billion websites, the VERY BEST THING about this business is that, thanks to public records, you can know the owner of every potential deal by name, and you can target them directly. How successful you'll be at that, depends mostly on what you have to offer. Reaching them is not the problem