So I put my ad balance setting to 44 % fill rate and 100% revenue. Is that ok?

The big discussion, starting when Adsense's new Ad Balance slider [webmasterworld.com]was first available covers it pretty well. For getting started, that might be the best place because it was new to AdSense and it covers a lot of questions.

This narrower topic is about Backup ads to Adsense [webmasterworld.com] and it is a much shorter discussion that may have suggestions and ideas for implementing the setup.

To answer your first question:
[support.google.com...]

So I put my ad balance setting to 44 % fill rate and 100% revenue. Is that ok?

That depends. Given that it is set a 100% revenue you should see very little if any negative impact on earnings. However, I would set it a little higher say 50%, because the numbers tend to vary over time and eliminating more than 50% of the ads may cause things to move around some. So set it, then watch it. Over time it should settle down.

Ok I notice the backup ads in the ad units page. But it only let's me point to a URL.. Is that correct? So I can place the backup ad code to a file in my server and fill in the url address into the backup ad settings?

Another question, if I setup the backup ad to be a pitch to advertise on my site, how do I make the thing responsive?!

how do I make the thing responsive

By making the page responsive. Adsense shows the backup ad url in an i-frame. So if you design the page to be responsive, it will resize when it is displayed. Be sure set your media queries based on the parent not the i-frame window itself.

The blank spaces are not looking good.

So if I link an image as a backup ad in a responsive page the image would automatically change size accordingly?

No, unless perhaps you set its width to 100%, but normally you would use CSS media queries.

Yep I placed the Ad Balance slider back to 100% 100% as my revenue decreased as the low paying ads were not appearing for my visitors from countries where monetization is tough and they are mobile visitors.

I was referring to the width of the image in your backup ad :-)

Sorry to learn you were losing revenue. Why not try something in between, though? A 60% fill rate, perhaps?

I started small with Ad Balance - 95% then 90%. Best to do it gradually so you see the results and compare day-to-day. I keep a detailed spreadsheet of daily earnings and jot down what the adbalancer is set at when i make a change to it. I'm currently at 85% and this seems to work for my sites. Anything lower or higher and I seem to lose revenue.

@CommandDork how do you attribute changes in revenue to ad-balance changes? I see wild swings in earnings, yesterday I saw 3x my average daily earnings, whereas on Sunday I was at 1/3, and that is without touching anything.

Yep the same with me also, my earnings go up and down anyways without adbalance slider settings... so I've decided to stop testing adbalance for now.