why do some apps load on reboot even though I'm not using them?

[snorge]

Not that the performance of my phone seems to be suffering much but it still bugs me that certain apps start themselves up after a reboot even though I am not interacting with them in any way. I have checked the settings for each of the apps doing this and even removed the desktop widgets (if they have one). Two examples are Shopsavvy and Pandora. It is once a blue moon I use either of these so I would like it a lot if theyd only run upon my request. Any ideas?