Free is good

At the end of the postmortem I wrote for my Windows Phone 7 game Jigsaw Guru, I mentioned I was about to submit a free, ad supported version of the application, since the downloads and sales of the paid game were extremely low. When Jigsaw Guru Free was released on December 29, I said I would write another post after a few weeks, and share some results. This is the post you are reading, I now have all the data related to the first month (12/29/2010-01/28/2011) of Jigsaw Guru Free on the marketplace, so let's get started.

Downloads

This should speak for itself:

Figure 1: downloads for Jigsaw Guru (10/23-01/28)

Figure 2: downloads for Jigsaw Guru Free (12/29-01/28)

The paid version got 103 downloads in over 3 months, the free one got 13 109 in its first month. That's 127 times more, in a shorter period of time. And if you look carefully at the first figure, you will notice the download rate for Jigsaw Guru increased a bit before the beginning of the year: that is because of the free version, even if it doesn't contain any information or link to the paid game (which was a mistake on my part), some people searched for and found the initial product after seeing the new one.

I don't want to state the obvious, but this shows your game has a much bigger chance to find its audience if it's free, and if it's not you probably should make a light but free version of it to let people know about your paid application. This is the same principle as on the iPhone, and as I mentioned in the postmortem, the trial mode implemented by a lot of Windows Phone 7 games (including mine) is not a good substitute for a free version, that system as it is right now unfortunately doesn't work (because it doesn't give your game any exposure outside of the section for paid apps, which has much less traffic).

Ad impressions

Of course it's good if a lot of people download your game, but if they try it once and uninstall it immediately, or never play it again, then what's the point? I don't have any analytics system built into Jigsaw Guru Free, to keep track of the number of active players, and sessions, and a bunch of other things, but  I have ad impressions. That basically tells me how many ads were displayed by the game every hour, I just can't see if it's a small number of people playing for the whole hour, or a lot more players only spending a few minutes in the program.

What's interesting is the number of ad impressions has been very stable for me so far. Of course it goes up a bit during the week end (people have more free time), and down in the middle of the week, but the changes are not drastic. Jigsaw Guru Free started just under  9000 impressions per day, is now doing between 16k and 17k most of the time, and served close to 420k ads in its first month.

eCPM

The eCPM (effective cost per thousand - shouldn't that be eCPT?) is basically how much money you get for 1000 ad impressions, so, that's a very important number. Unfortunately, unlike the impressions themselves, it can vary a lot from one hour to the next (or at least that's what I saw in January). Which makes it difficult, if not impossible, to predict how much ad revenue you're going to get the next day, since revenue = impressions / 1000 * eCPM.

Many factors have an influence on eCPM, I only know a few of them, and some are out of our control: for example, if a lot of advertisers are running big campaigns at the same time, eCPM will go up, since there is more demand for ad space; on the opposite, if it's a more quiet period, eCPM goes down, like it did in January. As developers, the main parameters we have access to with the Microsoft ad SDK and the corresponding pubCenter website are ad categories, application keywords, and phone location.

When you create an ad unit, you can select up to 3 categories of ads you want to receive. These can be really large categories such as "Sports", or more targeted subcategories like "Sports - Skiing". This selection seems to be the most important step in getting a good eCPM, but there is no list of what the 3 best categories are, and if there was one it could change over time anyway. The good thing is: categories are not hard coded in the application, they are defined on pubCenter, which means you can change them at any time without submitting an update, and the new categories are used instantly or in the next hour as far as I can tell (I changed mine one time in the middle of January). You can experiment as much as you want, maybe changing one category at a time, but don't forget that many other factors affect eCPM, and you're not necessarily always comparing apples with apples. 

I have one piece of advice though: don't choose categories based on what your application or game does. That's what I initially did, because that sounds like a good idea to have a better click-through rate (CTR, percentage of ads being clicked / tapped when they are displayed), and for example one of my categories was "Travel", since the photos provided in Jigsaw Guru Free all show places you may want to visit while you're on vacation. I'm not saying Travel is a bad category, or Astronomy is a bad category (someone in the forums mentioned he was using that one), but how often do you see advertisement about travel and astronomy, compared to some other products? So, my advice is to just look at commercials you see a lot on TV or in magazines, and pick the categories they would fall into: if companies making these products spend a lot of money advertising them in other media, there's a good chance they (or their competitors) will do the same on mobile phones. CTR may be one of the factors secretly influencing eCPM, but even if it does, categories have so much weight right now that it makes more sense to focus on them first.

Application keywords can be specified in your code, which means you cannot change them without submitting an update. This is not a problem for now: they're not taken into account by the current version of the Microsoft ad SDK anyway (this could obviously change in a future release).

Finally, your program can provide the phone's location to the ad manager (XNA) or control (Silverlight), and this can increase your eCPM if some campaigns are specifically targeting the area where the user is when he's playing your game. I have no idea how much of a difference this can make, but it cannot hurt. Just be careful and re-read the certification requirements if you implement this: you need to ask customers if they want to allow your app to use the location or not, and they should be able to opt out at any time.

Ad revenue

How much money did I make in one month with Jigsaw Guru Free? I won't give the exact amount, but here is what I can say:

• much more than I did with the paid Jigsaw Guru. Especially since the latter is still very far from reaching the payout threshold, and I may very well never see a check for it.

• with about 2 million phones in circulation right now, and 13k downloads of my only game on the WP7 so far, the ad revenue doesn't pay all my bills. This is to be expected, let's be realistic, I'm not disappointed at all.

• on the contrary, the good news is what I made in January will pay for my rent in Southern California, in March (since I should get that money at the end of February). This is a pretty good start, and with a couple more projects on the market, or some ports of the same game to other platforms, I could eventually be able to balance my budget in a few months if everything goes well. It's certainly not a done deal though, this will depend a lot on how eCPM evolves in the future, how successful my next game is, etc. But there is hope :-)

Free is good

Making a game available for free has a couple more advantages I want to mention. The first one is related to piracy: since the game is free, I don't have to worry about people eventually managing to install and play it without buying it, actually the more people have it the happier I am.

The second one has to do with Android: I don't know how that happened, but apparently customers on that platform are used to getting everything for free, to the point that it's now an expectation, and even Angry Birds was released as a free ad supported game. I find it kind of sad that people are not willing to spend a few dollars on a high quality product (after all, the persons who developed it need to earn a living, don't they?), but at least if I ever want to port something to Android I won't have a problem with the $0 price tag, since that's the one I would choose anyway.

Free is good. My next game will definitely follow that path, the only question is whether I will also have a paid version with some extra features and without ads, or not.