They are driven by the market, etc.

I have one per property, and at the end of every month I enter each booking line by line with data points provided from Airbnb/VRBO. 

(Only 25% of our ad-driven web traffic comes from Craigs List) We post our homes on around 50 websites.

Extrapolating that to today, the trillion dollar bailout/stimulus/giveaway/whatever you want to call it is being driven by massive unemployment, so I would conclude risk of inflation is low to moderate. 

Are they sharing actual data and first-hand knowledge, or are they just sharing what they've heard from someone else?

@Kristina XieMetro Detroit (my rental portfolio is here)Purchase: $80k-$130kRent: $1200-$1450ROI: Double DigitCash flow: $200-$350/month Appreciation: Double digit (for past 10 years, will gladly send data)Location: C, B- (suburbs and certain markets)We have over a dozen Fortune 500 companies just in Metro Detroit with huge Healthcare and Auto industries.

What is the best resource for rental vacancy rates data?

I have driven it, and I see a mix of cute, well-maintained houses with some kinda scary ones.

I use it as a data point, but not the gospel. 

I have driven HER around and have taken HER to lunch to show my appreciation and also to show that I"m serious and so she won't give up on me.