This is a guest post by David Barnes of Packt Publishing. It was originally published on his blog, facebook indie games and is reprinted here with permission.

Guy Kawasaki states as one of his 11 laws of bootstrapping:

Forecast from the bottom up. Most entrepreneurs do a top-down forecast: “There are 150 million cars in America. It sure seems reasonable that we can get a mere 1% of car owners to install our satellite radio systems. That’s 1.5 million systems in the first year.” The bottom-up forecast goes like this: “We can open up ten installation facilities in the first year. On an average day, they can install ten systems. So our first year sales will be 10 facilities x 10 systems x 240 days = 24,000 satellite radio systems. 24,000 is a long way from the conservative 1.5 million systems in the top-down approach. Guess which number is more likely to happen.

It’s much harder to get a big enough number with bottom up forecasting. You soon find that you need to take action and make changes to drive the numbers up… actions that you wouldn’t have bothered with if you’d used a top down approach.

Forecasting for Games Studios

How does this apply to game studios?

In a top down model you start with the whole market — a very big number — and work down from there. In a bottom up model you start with yourself, and work up.

If your forecasts start out using assumptions or data like:

There are over 200,000,000 iOS devices in existence. The top Facebook games attract up to 100,000,000 players. Minecraft has made more money than Dr Evil would dare ask for

Then you are using top down forecasting. The next thing you always say after this kind of statement is “if we could only capture just 1% of that then…”. 1% doesn’t sound like much: anybody could do it right? No, they couldn’t. Specifically, you couldn’t. Not like that.

Strategic Forecasting

Bottom up means you start with your situation and capabilities — pretty small numbers, I bet — and work upwards to hopefully a decent number. You might look at all the options you have to drive views to your game’s web or app store page, and make assumptions about how many visits you can deliver through various channels. And then think about how likely each view is to convert:

We have 2,000 followers on Twitter. Let’s aim to get 50% of them to view the game, with 10% of them converting to a sale. That’s 100 copies. Our web site gets 500 views per day. Let’s put an ad on each page. We might get 20% of visits to click the ad, and 10% of those to buy. That’s 10 copies per day. If we get featured by Apple we can expect sales of ~500 per day for a week. We’ll assume we get positive reviews on 3 fairly popular review sites. Let’s assume 10,000 people read those reviews, and 1% of them go ahead and buy. That’s 100 more copies.

As you can see, not happy numbers. But that’s the point: this kind of forecasting reminds you that you need to find more ways to publicize your game, and that a big market doesn’t guarantee success on its own.