I included AdMob ads in the latest 2 releases of MarketEnabler and it's running now since 27.11.09 so I can't say that much about Advertising with AdMob.
If you don't now what MarketEnabler is, see http://market-enabler.googlecode.com
Until now, I'm not very pleased with the ads from AdMob for various reasons:

The revenues are not very clear, I don't know exactly how they come together (I think this is on most ad providers)

The Fill Rate is sometimes very low and with logcat I see that AdMob SDK puts out a lot of "no socket" or "socket timeout" with NullPointer exceptions

I chatted with some MarketEnabler users and other app developer with AdMob advertising and all say It shows always the same ad (maybe two or sometimes three different)

The adds are stupid and not related, this leads to very low clickrates and I have to say for myself, I don't click ads that are just about free ringtones or free videos (some users had also the advertisement from god)

I personally would prefer an advertising that is related to Android and the Market or better said advertisings from applications that are on the Market and on click it will go directly to the market and you can buy them if you want.

If someone knows such an ad provider or if some developer wants to make direct advertising in the MarketEnabler app, just mail me or write a comment to this blog post

Some facts and figures for you now from the first days of AdMob in MarketEnabler:

27.11.09 => Request: 12687, Impressions: 12623, Fill Rate: 99.50%, Clicks: 8
28.11.09 => Request: 23487, Impressions: 23487, Fill Rate: 99.70%, Clicks: 20
29.11.09 => Request: 29316, Impressions: 29252, Fill Rate: 99.78%, Clicks: 21
30.11.09 => Request: 44571, Impressions: 33848, Fill Rate: 75.94%, Clicks: 24
01.12.09 => Request: 47828, Impressions: 37856, Fill Rate: 79.15%, Clicks: 12
02.12.09 => Request: 46849, Impressions: 42933, Fill Rate: 91.64%, Clicks: 31
03.12.09 => Request: 40781, Impressions: 38914, Fill Rate: 95.42%, Clicks: 16
04.12.09 (until now) => Request: 48902, Impressions: 36825, Fill Rate: 75.30%, Clicks: 19

Most of the users that are tracked are from Europe (mostly from Sweden, Norway, Finland, Denmark, Netherlands,...) with 128'199 Requests and then Asia (mostly from China, Russia or Malaysia) with 58'474 and North America (mostly from Canada) with 40'063

My question to all the MarketEnabler users about the AdMob ads is: Are they acceptable or not and what would be the kind of ads you would like to see in MarketEnabler?

In the end, if I don't find an ad provider that fits good into that (having Android apps advertising with direct market links) I will have to setup something for my own (the idea is already in the pipeline).

One word for the people that donated to the MarketEnabler team: Thank you for your appreciation and I promise to bring out a fresh (recoded) release without the busybox dependencies (and if my idea works, also for non root users) as soon I finished my other work (my pre bachelor thesis and I hope this is before Christmas, design review is on Wednesday).