Sure, a basic VPS could be a drop-in replacement, but think of all the stuff that goes on with managing that.  If you want to automate the creation of new servers then you have to script it or use something like CloudFormation or Troposphere.  Either way you are immediately off the &quot;drop-in replacement&quot; path unless you build a middleware layer for your scripts.<p>These guys make their money off the companies that need to be able to automate infrastructure and that stuff is becoming more, not less, fragmented.