Androidsx is now Perops. Visit us at

Androidsx Androidsx | android and wearable developers


Subscribe for market insights and new posts


How a simple dialog increased the sales of our Android app by 260%

March 28, 2011 at 8:08 pm | android, blog, monetizing | 12 comments


Short version. By introducing a dialog in our free application that encouraged the user to purchase the ad-free, paid version of it, we increased sales by 260% in the first week: 20% of the users clicked on the Go PRO button and, out of those, 15% finally bought our paid application.

Long version. We launched Spell Checker back in May 2010. It has been downloaded a million times (actually 985072, but come on, it sounds so much more cool), and has 60% active installs. It is ad-supported (by Admob, but it used to be Mobclix, see our experience with them here), and it doesn’t do too bad, with a eCPM of $0.09. The paid application is Spell Checker PRO, which is the same application, but without the ads. It used to be named Spell Checker Donate, in order to be very clear about the fact that there are no extra features.

It turns we need a user to click 70 times over our ads in our free version in order to generate more revenue than the paid one. We know this after doing a couple of operations over our Admob numbers. So, it is clear, we need to increase our conversion rate. (Still, we had a glance at our Flurry analytics, 18% of our users use our app more than 4 times a week. Not bad, but 40 clicks are way too many!)

What we did is dead simple: when you’ve used the application for 3 times, you get this dialog:

Go PRO dialog in Spell Checker

Go PRO dialog in Spell Checker

In order not to bother the user too much, we’ll wait until he has used it for 5 additional times before we show a similar dialog. Then, we’ll show it 8 times later, 13, 21, … (By the way, can you guess the next number in this sequence? :) ). The text will be slightly different each time, sort of like “So, do you like it now, or still not sure?”. Also, for existing users the message is a bit different.

While we analyzed this and other alternatives, we of course wanted to based our decision on numbers. Our estimate was that 2.5% of the active users would convert:

  • 50% of the users won’t even get to see the dialog in the first month. They are not active enough. This figure comes from our Flurry stats.
  • Out of the remaining half, 5% of them (1 out of 20) will hit the “Go PRO” button and buy it. This figure comes purely out of our air.

That sucks. We have no idea how many users will decide to buy it just because we suggest they do it. But now we know!

This pie chart shows the ratio of users that chose Free, 80%, versus those that decided to go PRO, 20%:

Users that choose PRO vs Free, from our Flurry stats

Users that choose PRO vs Free

We have matched the absolute numbers here with the actual revenue in Checkout, and it turns out that only 15% of them finally performed the purchase. That means, 3% of the users bought our application just because of our dialog. 3% is 15% of those 20%, and represents the magic ratio that we guessed out of air.

As a consequence, our daily revenue has grown by 260%, comparing the first week after we implemented this to the preceding weeks.

We are aware that the daily sales will considerably shrink after the dialog has reached most of the existing user base. So, of course this 260% won’t work for a new application. But it remains true that this has been the impact on our numbers, and hopefully all this helps you in your own estimates, which is our main objective with this post. Social behavior is so unpredictable!

We are just starting out in this fascinating world, and are aware that we are not good at selling. So help us a bit: how would you suggest we increase our conversion rate?


Can’t get our money out of Mobclix [Updated]

August 21, 2010 at 9:20 pm | android, blog, monetizing | 81 comments



September 12, 2013: Indeed, Mobclix scammed us. They didn’t pay us for almost a whole year now. We had most of our ad impressions directed to them for quite a while, so they have definitely made good profit off of us.

August 24, 2012: They just generated and executed the pending invoices. That was a quick reaction on their side! Still, we have not managed to match the figures of the monthly invoices with those on Mobclix’s Revenue tab (it would be great to know how exactly those are calculated).

Original post

This post is related with a comparison we did between Admob and Mobclix. Look at the Admob vs Mobclix: 1st round, 2nd round and 3rd round.

Find the updates below.

Will those numbers in your Mobclix analytics page ever turn into real money? Apparently it’s not so easy. And we are not the only ones, see here and here.

In short: we started generated revenue on March 2010 and now, in August 2010 and close to 5-figure numbers, we didn’t receive a single cent.

Long version: see our discussion with Mobclix support below.

Delayed payment

This is the e-mail that we sent on August 12 to Mobclix support:

During March, our first month with Mobclix, we generated $268.09 with our applications:

FML (803e8557-b71d-4937-b23a-8802ab22b125): $35.97
MLIA (cdf3868e-16b2-4611-ae83-4c6736400c50): $86.85
TFLN (cbc66b89-e88a-4e5e-8eb1-f3dbd36faf84): $145.27

Our questions are:
1) Why did we not receive any payment yet?
2) Why does the Invoice for June 2010 says $69.72? (Instead of $268.09)
3) Why didn’t we receive any payment yet? (We forgot this question in the original message)
These questions equally apply for the following month, April (whose invoice was generated during July)

The answer was just a document with the invoice for June (March’s revenue), splitting the contribution from every ad company. To this, we replied explaining what exactly were the mismatches between the figures in our Mobclix analytics and those in the invoice. In short, it should be 4 times bigger.

The answer was:

Mobclix will make payouts when we receive payments from ad networks. So while you may not be paid for a certain network in a month, we are working on collecting the payment and will remit it in your next invoice.

Irregularity in Revenue reporting

This is a different issue, and pretty worrying too. This was our ticket to Mobclix, on August 12:

In the Revenue tab for our applications, we noticed that, for 21-27 July, the generated revenue figures dropped a posteriori, after those days had passed. We can’’t find any reason or official explanation.

More specifically, here you have a table with the comparison of the figures that we observed before and after July 31:

27 July62.40$39.53$
26 July66.10$34.70$
25 July73.32$34.28$
24 July78.62$37.70$
23 July73.18$36.93$
24 July78.05$27.53$
23 July61.12$32.44$

We never got an answer.

What’s funny is that, if we hadn’t seen this, we would never have noticed. Maybe you think you made 100 dollars per day last month, but it has now magically to 40. No kidding.

Next steps

We still have hope that Mobclix will react, and understand how serious these issues are. We’ll keep you posted.


Admob vs Mobclix: 3rd round [Updated]

August 21, 2010 at 9:15 pm | android, blog, monetizing | 7 comments


This is the third part of a series of posts, look at the 1st round, 2nd round, and some related problems.

In our previous posts we didn’t cover a critical topic: how to cash out the revenue (ie, money) that you generate.


Every month you get paid the revenue you generated two months before. For instance, on July you get a transfer of the revenue you generated during May. As simple as that.


We started generated revenue on March 2010 and by now, end of August 2010, we have not seen a single dollar[1]. Ouch. That’s not a good business, is it?

This deserves a post on its own: Can’t get our money out of Mobclix.

[1] Update on August 24: We did get paid today.


Admob vs Mobclix: 2nd round

June 9, 2010 at 10:55 pm | android, blog, monetizing | 23 comments


This is the second part of a series of posts, look at the 1st round, 3rd round, and some related problems.

It’s been three months since we migrated to Mobclix from Admob, where we stayed for over two months. So we want to share some data, mainly focused to get our fellow developers starting out in the Android world to better estimate what kind of revenue they can make out of advertising.

We will compare the results for four weeks, aligned by the week day, using the data from February/March for Admob, and April/May for Mobclix.

This is the revenue that we generated per day (*):

And here, the revenue per click, which is our preferred indicator to compare how different ad providers perform:

All this has been generated by three applications, that currently have 100k active users (after over 200k downloads). It is difficult to keep track of how many users we had in each ad provider at every point in time, so comparing absolute numbers, like we did in the first graph, does not yield relevant conclusions.

In an upcoming article, we’ll show values that analyze the long term figures!

(*): We have multiplied all figures by a factor k € [0.2, 5.0], in order not to disclose our real numbers while providing meaningful data. This correction is consistent, i.e. if you have 2x active users, expect a similar price per click but double the revenue per day.


Admob vs Mobclix: 1st round

March 25, 2010 at 1:26 pm | android, blog, monetizing | 39 comments


This is the first part of a series of posts, look at the 2nd round, 3rd round, and some related problems.

We have been using Admob for three of our applications during two months. Our first impression was very positive: we generated way more revenue than what we expected.

The revenue per day was very unstable. In the last weeks, it went sharply down with no apparently reason (almost 30%-40%). We tried hard to understand how the Admob network works internally, with no happy end. We have more users, more impressions, more CTR but much less revenue… (stay tuned for an upcoming post where we share our stats).

After some twitter posts trying to find fellow developers with whom to share experiences, we were contacted by a Mobclix employee suggesting we switched to their mashup of agregated advertisement networks.

So, we tested Mobclix with the smallest app (in active users) with ads that we have, the MLIA widget:

Here it is the comparison between Admob vs Mobclix in MLIA over the same days, it looks really promising!

Admob stats

23-3-20103123 $0.50912.83%$2.93

Moblix stats

23-3-20103,313 $1.53892.69%$5.06

Still, it is very soon to draw firm conclusions. This is the start of a series of post with the comparative.



Recent posts: