In software, the 80/20 rule is a harsh reality.  It has two equally distressing parts:

1. 80% of your feature set is common while 20% is unique. 
2. 80% of your time going into creating 20% of the features

Part 1 should be a good thing – 80% of what you build will help all your customers.  Unfortunately, “unique” means that 20% of what you invest in will only help a fraction of your audience.  No problem you say? 

How do you know WHICH 20% is the unique part and which is the 80% common part?

Not knowing the 80 from the 20 is where Part 2 is particularly unkind.  Since you spend the majority of your investment on features for a narrow audience, you’d better get that pick your top features wisely.

The cold reality is that is that it’s not obvious which features are included in the 80% and which are in the 20%.  If you want to build a successful product, you need a way to pick the right features.

At most 50% of the features for a product are obvious in advance.

Let me explain using my last “next big thing” as an example.  I’m built a mobile sandwich application called sAndroidwich™.  Here are my product manager’s 10 features (in rank order):

1. Bread (top)
2. Bread (bottom)
3. Bacon
4. Romaine Lettuce
5. Tomato
6. Tuna
7. Smoked Turkey
8. Hummus
9. Pepper Jack Cheese
10. Cheddar Cheese (developers think Cheddar is easy if you already know Jack)

It’s pretty obvious that we’d identified BLT as our core market because everyone loves bacon, but what about the next 5 features?  Our product manager has 25 years of experience consuming sandwiches and swears that he knows this market inside and out.  Will these features put me into the top 3 social food apps?  You bet!  Call up Y Combinator, we’re going to IPO!

My potential feature list should have looked more like this:

• Feature #            Features
• 1-5                          Bread, Bread, Bacon, Lettuce, Tomato
• 6-8                          Turkey Market: Turkey, Jack, Mustard
• 9-11                       Beef Market: Beef, Cheddar, Mayo
• 12-14                     Tuna Market: Tuna, Munster, Pickles
• 15-16                     Veggie Market: Sprouts, Hummus

That’s 16 features even though I only have time for 10!  In addition to simply listing more features, I’ve also added market segments.  It’s important to remember that 80/20 rule also applies to features by market so features for 1 market may not help (or even hurt) sales in an adjacent market.

The challenge to picking features is that 50% of them are common to all users and their use is obvious while 30% of them are common to all users but you can’t distinguish them from the unique features.  I consider these to be “nonobvious common.”  You should take the time to list 160% of your potential features if you hope to find the real 80%.

To figure out the 30% nonobvious common features, you must accept that your own experience and bias clouds your judgment.

If you make the assumption that you can predict which of the features in the 80% and which are 20% then you will be wrong about 50% of your feature set!  If you accept that the second 50% of your features can only be discovered by customer interactions then you’re open to discovering the hidden 30% of common features.

Discovering this hidden 30% is critical to success because they are your market differentiation!

If you can find the hidden 30% then your competitor is probably handing you the golden goose.  In most cases, they are waiting while their engineering team is building the wrong features or focusing their 80% effort on the less critical 20% features.  This behavior ultimately causes feature fan out – which will have to wait for a future post.

BTW: sAndroidwich™ never made it into the top 10 apps – my team’s bias toward tuna and hummus (omega 3s AND delicious) meant that we missed the super-hot Beef and Jack market.   If only we’d shipped the BLT features (using Lean) then market tested and added incrementally, we may have been able to adjust before iSubpad and Po’Berry got all the users.