How to choose the best Mobile Ads Network for Android games?

Like establishing a website, one of the greatest motivations of creating android apps/ games is that, you can earn money in return, through advertising. In fact, there are tons of choices in the market, with each boasting of the high eCPM and revenue. The thing is, some of them even pay for writing non-justified commercial reviews in the forums (or creating a website for that), which further misleads the developers like us when making decisions.

When asking "Which is the best Mobile Ads Network" or "How to choose the best Mobile Ads Network", it is really tough to identify which facts on the search engine could really be trusted. I am personally a developer who hasn't been 'bribed' or paid for writing a discriminated review. However, i think it is appropriate to share my own opinions from time to time, at least for your reference about which options that i have tried before. And you can always correct me if i am wrong.
* I will always update this post whenever possible.

Admob
After realizing that Admob has been acquired by the Google, it is my first priority (and first attempt) of the mobile Ads network. It features a banner Ads that i liked to place at the bottom of the game display. The thing is, with the 50-100 downloads per day, the earning of Admob is pitifully low at around $0.50 - $1.00 per day. I have to honestly say the figure isn't that impressive (but at least i did earn something). After obtaining like $50 for the first time, i looked for some alternatives.

Revmob
I came across this mobile ads network in the forum. Some of the members have highly recommended this for a high revenue. I am attracted by the clean insterstitial Ads interface. However, after 2 months of advertising with this network, the stats shows dismay figures as well. Sometimes the number of impressions and installs don't really reflect your potential revenue. And the eCPM is even lesser than  3 (not even closed to the figure claimed at here). The support did respond quickly, but it was said that the number of impressions are not sufficient for the analytics. I will see how before adding more comments here.

Updated on 01 Oct 2013
Alright. After 3 months of testing, I would say Revmob generates poor results, at least for my Android game, despite the facts that the majority of the downloads come from the advanced countries like US, Korea, etc.

Vungle
This is the mobile ads network that caught my eyes in the Techcrunch tech geek site.. It only features a 15-second video ads (but it is quite special). The HD video quality is amazing. The Ads is pre-cached as well, providing almost no overhead when loaded. However, at the time of writing, the SDK only supports a landscape mode of video. If your gaming experience would be affected by the landscape mode, perhaps you need to wait for the future release. I would make more comments after having enough stats.

In the end? You are right, so far I haven't really found out a special mobile Ads Network that could really stands out (but i hope i am able to in one day, and update here). Furthermore, since different games have different gaming experience (and hence the Ads display), the comparison of the performance could have a slight discrepancy, unless all the games (that are using the different networks) are designed in a similar way.

Below shows the Alexa Ranking of some, as a reference of how popular the Ads networks are:

Mobile Ads Network	Alexa Ranking
Admob	4909
Revmob	29427
Vungle	81393

Apart from that, you may get some information from here.

Note:

• Some Ads Network have 'biased' results. For example, Revmob claimed that it has a higher revenue in iOS than in Android.
• Different Ads Networks have a different threshold for payment. For example, Admob pays if the accumulated amount reaches $30, while figure of some others is $100.
• Since Admob is acquired by Google, i would say that it is much more stable than any new start-up. The Mobile Ads Network industry is very competitive, such that you may never know which one will shut down taking your money away tomorrow. Remember the death of Adbrite last time?