I made £300 in a month when first starting out, with a very bad directory site that got bugger all traffic - my biggest sales were £100 for homepage links, and that was with an old niche directory idea.
I don't know about levels, but it was in the top 5 directories for link capturing with 80k of links in 2 years - but that was back in the good old days, when people just gave links away

Its very difficult to get links now, and it will get tougher.
My point is that young websites won't do well bcos their er, young..... they have no rep, zero links, no link value, low traffic and a young domain - plus the idea cant be that good or it would be an instant hit like Youtube. And you can only charge and make any money if your website is established for many years - this is true! Although there are exceptions, which are few.
The web idea is crucial to success, and the vast majority of websites just won't get anywhere, no matter what they do promotion-wise.
Very tough to get people to spend on an unknown, unrecognised website - no matter if its product sales based or info based. Trust must be earnt, and comes way before money changes hands.
Someone mentioned 'Standing Out' and thats exactly right and what a
web platform must do. If a site can get say 50k of traffic per month, that would be classed as phenomenal, and then has worth to advertisers. But those traffic figure apply to web resource sites - and NOT biz product sites, you won't get 50k of visitors hitting the average product sales biz site.
So to ask for ad fees, you need a great idea, money to sink into the project, a ton of press attention and trust from buyers...