The last single point source I have was published in I believe 2014 - so it’s hopelessly outdated.  

Look for properties with outdated kitchens or bathrooms, as these updates often yield high returns.

This is despite there being other similar single-family home listings in the area that are not grouped in this way.I contacted Zillow about this issue, especially since when I search for my specific listing directly and click on the public view, it shows outdated information (e.g., old history) rather than listing it as available for rent.What is going on with Zillow’s listing display?

Sure the site is a little out-dated in appearance but it is so user-friendly and although it isn't my highest producing lead source, I do tend to get very strong leads from there and no spam so far. 

Despite minor updates it is outdated.

I tried DealMachine for the lists/mailers; however, many of the lists I wanted wouldn't pull and the one that did pull was super outdated. 

Sometimes Google is outdated.3.

Unfortunately, some realtors don't respond to their phones, some HOAs have outdated contact numbers, and some CC&R documents are not up to date.

I do think some of your points are outdated though.

They don’t effectively target motivated sellers.In fact, the market is saturated with these outdated and inefficient approaches.