I've been thinking about this for a while and noticed this behaviour amongst my friends. I have one friend who is a true apple fan-boy and finishes his phone contract early so he can get the latest iPhone earlier at much cost etc.
I recently finished an app and said - hey, do you mind downloading it for me and checking it out? He says, "but it costs £1?!" I said, "ok, no worries, I'll GIVE you the £1 right now"
He still said "No". Why? Because "he never spends money on apps." Weird, right?
Then last night I'm watching Horizon - "How we make decisions" [1], and they talked about how when we feel we are ahead we are much more cautious than when we feel we are behind, when we experience "loss aversion" and are more likely to take a gamble.
I wonder if this is the best way to monetize apps. So you offer the app for free (no risk at all), then instead of offering "add-ons", you offer to remove "restrictions", implying that the user is already behind and they should take the gamble to get back to their "free" app.
[1] http://www.telegraph.co.uk/culture/tvandradio/tv-and-radio-r...