Reading Caurmen's mobile appetizer and he says to avoid "direct APK download" offers, what does this mean & why is it a good idea to avoid them?
Thanks
Craig
Yes as @vortex says, .APK is an app package for Android that you can directly download to your phone. The problem is that many time its used to distribute malware or other malicious code.
Also on some devices it's directly starting to download without need to confirm it.
Most ad networks do not allow direct linking these offers, however from my previous experience direct linking works best for these 
Yup, that's correct.
Some offers will be pushing APKs that for whatever reason they don't want to or can't promote through Google Play. Thus, in order to convert, they require users to download and manually install the APK.
That requires the user to be so incentivised to install that they are willing to go searching in their phone settings for an obscure "allow APK installs" setting, and ignore the dire warnings that come with it.
As a result, direct APK downloads tend to convert like shit.
In addition, a lot of traffic sources don't like them, because direct-download APKs are strongly associated with malware, and because for a while people were using a trick to just have them download on any phone that viewed a certain rich-media banner.
As a result of both those things, I'd recommend steering clear of them. They're usually presented as standard install offers with payouts that aren't high enough to justify the difficulty in getting them to convert.
(It's also worth noting that anything that can't be submitted to the Google Play Store tends to be more than a little shady, so even if you're not fussed by the above issues you should also consider if you're comfortable with that before running them. )
Thanks Caurmen, Vortex & Eric. So to summarize APK offers are basically those which come prepopulated on the users phone and they just have to click them to install/download eg. something like Gmail or Netflix. Would you say the same would apply to an app that is already being sold in the google play store by the advertiser and the affiliate network says is in their top 20 for revenue? As in I would be competing directly with the advertiser if I advertised in the app store, so maybe I should avoid it altogether or try marketing it else were, like in app advertising. What do you guys think? The app is already excellent conversion in major markets (I used app annie, but use the app daily anyway so I know its money). I have opportunity to market it in a non prime market.
Actually to answer your questions, yes I noticed that some app developers have also their APK version of the app, with lower payout, but possibility to send incentive traffic to it, but most of the times its not the case and these APKs are totally different apps. Many times they are fall under adult category.
@njerseycraig - no, APKs don't come prepopulated on the user's phone. They still have to download them. And then they have to go through a specific series of settings steps to install them.
Regular Google Play Store offers would be the ones that are a one-click install.
If the app's being sold through the Play Store normally, you'd usually also be promoting the Play Store version if you're running an offer for it.
Can you give us a bit more information on the situation you're looking at? I'm a little confused as to exactly what you'd be promoting and I don't want to give you the wrong info there.
Thanks for the input. The offer is to promote Uber in a non-major market. Im guessing promoting in the app store itself is a bad idea because Uber itself will be promoting the offer here. So I was thinking good ideas would be to promote it in other places. What do you think?
Is this a conventional affiliate program? If so, your affiliate link will probably direct people to download from the Play Store / App Store anyway.
I wouldn't worry too much about competing with Uber themselves in this case - generally if a large brand is also running advertising at the same time as you're promoting them, the additional awareness generated from their ad spend helps rather than hinders campaigns.
Thanks for all your help Caurmen. Not sure what is "conventional" but I'm guessing it would take them to the app store to do the install.