Better mobile ads
Mobile advertising when referring to smartphone devices and tablets specifically, means understanding the different marketing tools that exist only in mobile, the type of engagement you get from mobile users and the marketing channels you should prefer that exist only in mobile, the key points off the top of my head:
1.
Fragmentation - this is the key word with mobile, you cater to a ton of different devices, browsers, and operating systems which means your display ads might not serve everyone with the same quality of service. You have to be more careful about how you target your ads and make sure and double test that you get the desired results across your targeted devices. This means resources in terms of making your site responsive to most mobile devices but will also mean you now have more targeting options and can better optimize your campaign. Most of the websites out there are still not responsive to mobile but that's a work in progress.
This will also affect your costs as, for example, some carriers are more preferred then others (pay as you go or pay-to-talk customers). Know what works in the country your working in to target the paying users.
2.
Native Apps vs Mobile web - Native apps mean apps downloaded directly from the app store, written in their native code, native apps allow more robust code / product and a better experience for the user than a html site, Apps also provide you with another marketing tool which is offerwalls, or incentivized leads or users that get paid to do actions within the app, like download your app or register. A lot of app developers embraced this solution as a way to monetize their freemium traffic and when done correctly can show you great ROI.
3.
Evolving space - Many of the tools you take for granted in online advertising also are non-existent in mobile where sometimes cookie-tracking cannot be applied, when dealing with app download campaigns which lead a user from his browser to the app store, it generates a download which doesn't happen in the user's browser but instead the app store, then the downloaded app. Cookies are not available in the appstore thus breaking the tracking chain, this means you need to involve a third party to close the chain or develop your own solution. which means more resource. This is one example but in general it means a lot of the tools you expect to be taken for granted aren't.
4.
Mobile users - there are many psychological explanations to what makes mobile users different, some say smartphone users have a shorter attention spans which means ads must be more engaging, more appealing and goals must be easier to hit, meaning streamlining content to get them to register or deposit in a couple of minutes.
5.
Limited results - due to the above and more user engagement is more difficult, on a screen 1/8 the size of a standard screen most sites still try to show users the same content, this means a tiny banner on a tiny screen which 50% of the clicks it does generate come from users with chubby fingers. This means it is harder to see the same return at first, but with optimization you'll see better value.
there's a lot more in terms of marketing strategies that are unique to mobile such as push notification campaigns or app ranking campaigns but I think that's a good start.
