This is simplified, according to the IAB. Exchanges may try to unload unsold ("remnant") space at low prices through other exchanges. Some agencies maintain semi-permanent pre-cached bids with ad exchanges, and those may be examined before going out to additional demand side platforms for bids. The process for mobile advertising is different and may involve mobile carriers and handset software manufacturers.
Find a profitable niche. Starting with your interests, write down as many niche ideas as you can. Think about topics people might search online. Ideas include passions (like surfing or body building), fears (like spiders or speaking in front of crowds) and problems (like getting out of debt). Do keyword research to see it others are interested in the topic. Find out if a domain name is available that matches the keyword 100 percent. 
Hi Dominic! Facebook does indeed reject advertising for the vast majority of dating sites, so you're better off looking at other forms of paid advertising. However, to the best of my knowledge, all the info on this page related to getting engagement, interacting with fans, etc. is still completely accurate, so the training is still good for using Facebook to drive traffic naturally, at the very least. :-)
We’ve all heard those horror stories about folks who accidentally published personal content to their employers’ social media channels -- a marketer’s worst nightmare. So to avoid publishing mishaps like those, assign Facebook Business Page roles only to the employees who absolutely need it for the work they do each day. And before you do that, be sure to provide adequate training to those who are new to social media management, so they aren't confused about when they should be hitting "publish," what they should be posting, if something should be scheduled first, and who they should be posting it as.