I had Adsense and self-hosted ads simultaneously for a while and had built a decent base of advertisers and contacts over the years so there wasn't much additional investment of time above what I was already doing.
Getting an advertiser on board with your program is the hard part, swapping graphics in and out is the easy part.
Very very interesting. How does revenue compare? Have you considered putting adsense ads on during traffic spikes or any similair strategies? Do you share any analytics besides impresssions/clicks/costs with advertisers?
The only time I've seen this is on my school's newspaper, and they are wildly unsuccessful.
At the time it was in my favor to switch, plus it looked weird and jarring to me to have several ads for office furniture and then one for that thing you bought on Amazon 3 months ago.
Re: traffic spikes, no. There are limited spots which can be purchased so adding more spots whenever I want wouldn't seem right to my current advertisers who bought based on the limit in place.
Edit: I also get contacted by ad networks from time to time saying I could boost my revenue, but I always ask which advertisers they have who are relevant to my audience. It is always none. So at this point, I'm relatively confident that I don't need an ad network to service my particular niche.
Ads are priced $/month and are sold in blocks from one month all the way to 12 months.
The site is on Wordpress so I just use plugins to handle that stuff. I'm basically a publisher so Wordpress is perfect for almost anything I could need to do.
Getting an advertiser on board with your program is the hard part, swapping graphics in and out is the easy part.