Guys, can't get something. Is it o'k when the company (sharkspace.com) offers unlimited parked domains for their resellers?
As I know there are some limits on that.

There are indeed practical limits. One would be the amount of space you have at your disposal.

You can park unlimited domains theoretically. But they must a http connection limit. So if any resold account that you hosted under your reseller exceeded it when they may suspend it.

Here in hosting industry unlimited things can only go up to a certain limit. You are also aware of that i think. At the point you are crossing the limit of your unlimited thing you will be thrown out.;)

I think that we should make the distinction between parked and addon domains. A parked domain is just a domain that points to a different domain. Such as gogle.com and google.com. They're not distinct web sites but instead gogle.com is pointed to google.com (or parked on google.com).

Theoretically the limit for parked domains could be very high without causing any real issues, however for addon domains it's a different story where each domain has it's own hosting.