This is a question I need answered in order to determine which website I will be launching. If for example, a site got 10,000 unique visitors a month, but each visitor stayed on the site for over an hour every time they visited. Would this site be more suitable to get advertising then a site that got 50k uniques but had visitors that only spent an average a few minutes on the site?
If you are doing CPM, just do the math based on expected page views from your two different plans. If you are doing anything else (CPC, CPA, commission, etc), you would want as many high relevancy visitors as possible.
The site does not sell anything. It's an ad based revenue site. Could be cpm or cpc. But your answer is flawed because if you were doing it by cpm and you had ten visitors who averaged 5000 page views a ad, you clearly wouldn't make money from that. So page views based on cpm is clearly not the answer to my question. Once again essentially my question is what's better for an ad based revenue site - a lot more unique visitors with time spent of the site pretty average, or a site that doesn't have nearly as many uniques but has exceptional time spent on the site for each visitor.
People who stay longer are always more likely to click and ad, make a purchase, etc. So yes the site would be more suitable for advertising.
Your original question gave two instances, long time on site for fewer UV's or more UV's with less time on site. My answer to your question still stands. You need to do the math when looking at CPM based on the page views that you would expect from each respective plan. No matter what your plans are, there are numbers involved that you can use to figure out whether CPM looks like a good option or not. If one of your plans would have 50k views from 10 visitors, you run those numbers along with any others that are relevant, and get your results to compare against the math you do for alternative advertisement types. Your original post did not offer up the ridiculous scenario in which you get 50k impressions from just 10 visitors that are on your site for an hour each (yeah, that's over a page viewed per second by each visitor). Even assuming you didn't mean the 10 visitors were each on the site for only on hour, and we assume fairly normal page views of around a minute each (for the typical type of site that encourages extended stays), you are proposing that these 10 visitors are spending an average of 83 hours and 20 minutes per month viewing your site. Hey, if that is what you are looking at as realistic for one of your plans, okay. You can still do the math based on any restrictions for each specific CPM network that you consider. You originally proposed 10k unique visitors staying on a site for around an hour or 50k for a few minutes. 10k visitors on the site for an average of an hour, assuming a tube site with short videos, a Q&A site, forum, or something along those lines (high impression models that encourage extended use), you would be hard pressed to see more than 60 page views per person as an average. Unless you have a site model where someone would use your site only once in a month, only for an hour, and not be recurring, those impressions would also be spread out over time. Even if you average 60 impressions per IP on a single day in a single 1 hour block of time, per visitor, I think you would be hard pressed to find a legit CPM network that would have a problem with that. If you want to consider even faster viewing, 3 page views per minute (20 secs per page, we would be talking Twitter or image site fast) over an hour is only 180 impressions per IP per month. If you are looking at a CPM network that would limit your payout after xxxx impressions from a single IP per month, that is something you factor in when you do the math. I took the information you gave and provided a response on how to look at CPM as an option. If you want to know what you would make from CPM vs another income source for each plan, the only way to give yourself a real estimate is to do the math for each of your specific plans to find out how much you can expect from CPM. Either CPM is something you are considering, in which case you need to run the numbers that are specific to your plan, or it isn't.