I'm now running MobFox ads in Announcify for less than a week, but I think I already know all you need to know about this service. Let's look at the facts:
MobFox is a one-man-company dedicated to mobile advertising. Also, it's based in Vienna. That's a big plus because I prefer things that come from Austria. But the plus doesn't seem to be big enough for MobFox...
Talking about jar-sizes they're almost head on head. AdMob: ~50kB, MobFox: ~30kB. I don't care much about that 20kB. Do you?
MobFox's instructions for how to implement their ads on Android are faulty. Really.
If you're an experienced developer that's definitely not a problem for you, but I guess some beginners could despair at this point. AdMob on the other hand offers docs, READMEs, FAQs and step-by-step guides too. AdMob.score++
MobFox's web interface looks... like... erm... AdMob's. Ok, there's nothing really bad about that. Most websites look identically. I'm just saying...
"Only serve CPC ads that pay a minimum of $ X per click." and "Only serve CPM ads that pay a minimum of $ X per thousand impressions.". Do I need to explain that any further?
The idea about MobFox Backfill is simple: If they don't have any ads to show which meet your requirements (eCPMcontrol...), they fetch one from AdMob or a few other ad networks. Sounds like a good idea, but it isn't.
MobFox eCPMcontrol + Backfill != money++
My experience was like that: I enabled eCPMcontrol and set it to the average recommended values. $0.10 CPC, $1 CPM. Until then I had a few thousand impressions and something like $0.30 a day. The next day I reviewed the statistics eCPMcontrol already took traction: 500 impressions and $0 a day. Cool! Er, wait!? That's actually pretty bad. Ok, no problem. MobFox Backfill and therefore AdMob to the rescue! Nope. No rescue for you. MobFox does indeed fetch ads from AdMob, but displays only the ad's text. No graphics. Why should users click on boring plain text ads (like I do have here on my blog! ;))? Also, they display a little "MobFox" at the right side. Is this legal?
Update: After some more fiddling with both AdMob and MobFox at work I think MobFox is better than it sounds in the paragraph above. For example, AdMob's fill rate is at something like 40% lately. It was as high as 90% before. If I used MobFox the chance for actually receiving an ad would be a lot higher. However, remember how MobFox displays AdMob's ads...
So, MobFox didn't make me sing "A Milli" like Lil' Wayne did after he earned his first million dollars. Did AdMob? No. Announcify is an app you open once or twice a month (or even less!) and forget about the rest of your time. It's very unlikely you click ads in this app. However, running AdMob brought me $0.20 a day. That's at least something if you earn it everyday without doing anything for it.
I'm sure this post sounds a little confusing, but it really depends on your situation which ad network fits your needs better. If your app's audience is mainly from Austria you're definitely good to go with MobFox.
Also, if MobFox didn't display AdMob's so strange I would recommend it to everyone. Maybe Mr. MobFox reads this post and considers changing this part of MobFox?
Oh, and if you want to sign up for MobFox (I guess it's always worth a try) please sign up using this link so I get some cookies for free. :)
Here's a pretty extensive comparison of ad networks out there, compiled by the company I'm working for, customLBS. Keep in mind that values like CPC and eCPM vary depending on time, location and your application itself.