I browsed MacRumors last night....pulled it up this morning and it was still on the same page I browsed last night.....
Maybe I'm not using enough memory to warrant a reload? I also don't open more than 2-3 tabs at a time.... generally just one.
I edited my post btw. I think your just not using the memory. Tapatalk and safari are the biggest too I notice. In safari it will retain the webpage HTML but not the webpage itself.
That's just the way it works. It's not a problem IMHO and I feel iOS and the apps do a good job at not reloading. It's just based on available ram and how much cache an app is willing to use. I rather stuff reload then turn into a huge storage monster like Facebook.
Btw when is apple going to give the option to delete cache without deleting the app.

The app is 37 mb. Only way to get that back is to delete the app. That is the "other" in iTunes. Blah, its certainly not an efficient file system at all.