What is the usual trend in the first few days, for app downloads?

I released my first app on 17 July and for the first three days there was exponential growth in the App Units downloads: 2, 10, then 23 app units. I yanked the app off the store to change something (not realizing as a newbie that there were more elegant ways to do this), and the number of App Units fell to zero of course.

When I relaunched the app a couple days later, I never saw this explosive growth return. In fact, the number of App Units per day has been 0 to 4, even as of 3 weeks later and despite the start of a small marketing campaign.

I rang Apple Support to check whether I'd flipped some kind of switch or joined a blacklist or something by yanking the app off the store, but they said "no". So I'm wondering now, is it common to have a surge of a few dozen random downloads of an app in the early days, followed by relative quietness?

Thanks for any sharing of experience of the first few days of your own app launches.
What is the usual trend in the first few days, for app downloads?
 
 
Q