Provide the theme summaries for the following conversation: 

Dana: I still haven't found the answer why the results differ so dramatically.
Jason: Well, there's the result rationalization, so if you search for a pizza place you'll find one in your neighborhood and not the most popular on the Internet.
Dana: I've read about that so I'm aware. More or less. But I even searched for it in different languages. Incognito mode. Different devices.
Jason: You just gonna get most popular results in this particular region and time. Apparently this book is not well known in Aus. Incognito mode just deletes cookies.
Dana: Still doesn't explain why I can't find an American writer. Even if I scroll through 100 pages.
Jason: Incognito doesn't hide your region.
Dana: So even if I run hotspot shield, it chooses my region? I've never heard anything like that.
Jason: Yes because there's a main host you get connected to first. And then there's your router, server, ip.
Dana: I've read about regionalization, it's merely a percent in the result variation.
Jason: That's not what I'm talking about. There are 2 or 3 main factors influencing what you you get.
Dana: I don't get it. I'm not talking about a pizza place but an English speaking writer. Should show up anywhere.
Jason: It probably should. But it doesn't ;) next time you travel try searching for him again. Use a different browser, log out of chrome, try a different device and let me know what you see.
Dana: Might be a while. I guess I just never thought how we get conned into seeing more of one thing than the other...
Jason: Yeah, that's one way of looking at it. But it also helps you get what you need faster. You just have unusual interests ;)
Dana: Maybe so. Thanks anyway, I'm gonna try and find out more. That mystery really has me startled...

Summary: 
Dana can't understand why the results differ so much. Dana can't find an American writer even though scrolling through 100 pages. Jason suggests using a different browser or devise. 