I stopped once I realized I could protect my principal from market fluctuation and get twice the income from my savings. 

All rankings fluctuate and vary depending on time of day, competition, market, etc.Thirdly, there is no way to "shuffle you among the spots" day to day - no marketing company can control this.You are absolutely right to assume this is too good to be true and should run, not walk, away from this as fast as possible.That said, here's what I think is actually going on here - some company may be trying to rank sites within your market, then sell the leads from that site.

Mainly needs to to liquid, safe, and not fluctuating around in value so when the time comes, it's dependable and accessible. 

You don't lock in a rate, so rates will fluctuate while you're under contract. 

Real Estate price fluctuation =/= rent price fluctuation. 

This of course is only if that "investment" doesn't change direction, the economy doesn't fluctuate, there are no other issues during that 17 period that forces you to add more cash out of pocket to cover...because if you do have to add cash out of pocket, that also adds to the amount you need to recover before you make a profit...and extends the timeline further down the road to making a profit.

The house would likely sell around 500,000 (3.5% APR) The rental rates in Jacksonville have fluctuated a bit the past few years, my total mortgage payment is 2600, similar homes are renting for about 2500-2750 in my area which has me thinking about it more as a liability than an income producing asset.

An example of uncertainty would be, flood insurance, a hurricane area where insurance cost fluctuate substantially, taxes, city regs,etc. 

Edit to add: due to market fluctuations and the ability to hold for longer than expected, I ended up selling the property for $110,000

Right now there are delays in getting some things and prices fluctuate widely on others.