Appraisal, what's the point?

[Stephen Rager]

I recently purchased two rental properties, both less than $50,000 each.  The appraisals cost roughly $475 each.  I'm wondering what was the point? I don't believe they were required to close.  Being new to this I did order them. Now I'm reviewing to improve my system to determine if and when an appraisal is appropriate.  In this case, this is to buy and hold properties.  

TIA