I get the distinct feeling that Tor uses the same identity/circuit from day to day. I use Tor solely to defeat (low) paywalls in online publications.
Say a newssite allows the reading of 5 articles per session/logon to that site. Unless I manually choose New Identity each day (I typically have one Tor session/day, then close it) then that site keeps count of the number of articles and I hit the paywall after a) reading the allowed 5 articles in one session or b) after reading 2 on one day, then 3 the next.
This suggests to me that the site in question can keep count of the total number of sessions for subsequent logins just as when using my regular browser.
This defeats the very purpose of using Tor I subsequently manually choose New Identity each day (session were I to log on several times that day).
So, can I automate this procedure of getting a new identity/circuit on each new session?