US mobile monetisation outfit Tapjoy is on a high at the moment.

It's rolling out new services, hiring new executives, raising more funding, and gaining support from more developers as it shapes up for a planned IPO.

But what really matters to developers is what sort of revenues they can expect to generate from using the techniques and services Tapjoy offers.

Obviously, this varies on a case-by-case basis, so in a slidedeck entitled Making Money on Mobile, Tapjoy's director of publishing Rob Carroll has provided some rules of thumb.

Matching big and little numbers

Carroll reckons developers should be able to get between 5 to 10 percent of their user base monetised in some form, whether that's IAP, adverts, or incentivised actions such as downloads or videos.

In this way, he suggests games with 'weakly integrated' virtual goods should be generating around 0.5 to 1 cent in terms of average revenue per daily active user.

This can been boosted massively to around $0.15 (15c) ARPDAU, however, if your game includes items that users really want.

The resultant differences in these ranges can clearly been seen by taking an example of a game with a million daily active users.

If you're generating 0.5c ARPDAU, your daily revenue is $5,000, while at the 15c rate, it's a much more impressive $150,000 daily. And some companies are monetising at much higher rates.

Yet, if you're only monetising 5 percent of your user base, you'll be looking at requiring at least 20 million downloads to generate one million daily active users. On that basis, generating $5,000 per day isn't good business.

Better best practises

Of course, Tapjoy's point is developers need to be thinking seriously about how they are engaging their audience in terms of UI, the types of items offered, and the psychological triggers behind such activity, so they can maximise the percentage of the userbase that are being monetised, as well as the average spend.

For example, on the basis of these figures, you could generate $1 million in annual revenue from a game with only 30,000 daily active users (maybe as few as 300,000 installs), monetising at a rate of $0.10. However, as soon as the ARPDAU and percentage of monetised users drops, the installs and daily active user rates required grow alarmingly.

Carroll suggests in-app advertising can add additional revenue, from around $0.35 to $0.90 eCPM, but rising to $2 eCPM for the top performing games.

Overall, he reckons such alternative monetisation methods can generate around 30 - 40 percent of your total revenue on iOS and around 50 percent on Android; which if recent figures from Distimo are to be believed are likely to be a considerable underestimate.

You can check out Carroll's slidedeck over on the Tapjoy blog.