Some questions about Impressions

Hello Guys!
I've few questions to ask you!

1) Let's say that I have 50k unique daily visitors: is it better if I have 5 website with 10k unique each or 1 website with 50k unique daily?

2) Is it better if 1 unique visitor generates 5 impressions or 5 unique visitors generate 1 impression each?

Thank you very much and sorry for my bad English.

1) One site
2) 5 unique visitors generate 1 impression each

Really it makes no difference how many people come to your site. If they come to your site and leave it does you no good. Yes you can say I had 1 million impression, but if they did nothing its really all for nothing.

I would rather have 1,000 visitors and they visit several pages and interact with the site. to me this is more value to a site hold than having a million people that come and drop right off.

Maybe I am wrong. but I want my customers to stay and interact with the site.

It all depends on the websites and your niche. If you had all 5 websites running for all different reasons, sure. However, if you had one website with everything in the same niche, that traffic would have an easier time finding you and navigating whatever it is on your site.

Perhaps start with 5, and scale the hell out of the best one after a little time?

Therefore are 5 impressions from 5 unique users each better than 5 impressions from one user? How many impression can generate one unique visitor? Is there a limit? Do you know what happens if some visitors start refreshing the website? I don't think that every refresh is counted.
Many thanks guys. Im so sorry for these n00b questions.

So 1 unique daily visitor can generate just 1 impression day?