again...I don't think you know about the user identification Google gives each machine..
check it out yourself using 7-zip and look at your cache..every time u revisit goigle they place the user id in your cache..then u search..if u clear cache and then go back to Google..same user id..so they know it's a revisit even if Ip has changed...as they allocate u an id each search....every search of your machine is recorded on their server..whether u clean your computer or ip.
doesnt matter how how many times u clear cache and change ip.
user id will give Google all the info they need on your search and time on site. every time u log back on they know it's you....they do show the statistics in analytics and it does improve alexa..but this is all it does..they show u statistics in analytics to make u think it works...but their algo goes deeper.
google installs Lso and other cookies.. Even hookies that will id network and machine information. Then there is .dat files, Google chrome installed on your computer...Google updater etc.. They store a lot on your computer that's not even just in cache. All this sends machine info to Google..to think Google just uses browser and ip and that they are dumb is naive.
check out their privacy policy and look for "device information"
if you gonna make something like this.. First of all it needs to be private and on many users computer..and the bot uses each computer. Second of all..changing machine and network information is safer to get fresh ID from Google.