I received an email from the CEO of another SDK-based technology company asking how we've been so successful getting developers to adopt the Socialize SDK.

I like to have conversations like these in public so that other entrepreneurs in the same position can benefit from what we've learned, and share their knowledge as well. What he's asking about is a very sensitive subject: Mobile app developers are already suffering from SDK overload, and the problem is just going to get worse before it gets better. Knowing how to successfully get developers to adopt and implement an SDK is a huge tactical advantage. Having said that, I'm not going to give away the many things we do at Socialize, but I'll give a bit of knowledge away in the spirit of doing so, and I'll hope that other entrepreneurs do the same.

First things first: For those of you who don't know the difference between an API and an SDK, here's a high-level analogy to baking a cake:

API vs. SDK: Like Baking a Cake. Click to Enlarge

What Socialize has developed is an SDK that gives any mobile app developer the ability to drop social functionality into their app. I recently wrote a related blog showcasing how these social features can help any company create Instagram-type viral growth through social actions.

The main tip I'll share has more to do with strategy than execution: Define your goals and then make sure the time, effort and money you expend on SDK advertising is consistent with those goals.

For example, our goal at Socialize is to be integrated into apps with 500,000 or more downloads. That means that we've mostly stopped sponsoring or participating in hackathons, because they tend to draw smaller indie developers. And while Socialize is really, really good for indie developers, we've grown to the size where us spending marketing dollars on smaller developers won't move the needle on our macro goals. (We do still offer fanatical support to any size developer via our Socialize support forum.)

Here's one trick I'll share around SDK advertising. I recently read this great post by Ben of Plenty of Fish about a different type of banner ad. I decided to try reproducing his results -- and boy, did I ever. Here's the standard banner ad we've been running in a very targeted fashion:

I tested replacing it with this hand-drawn version:

Conversion rates were consistently 200% to 300% above the regular version:

I don't yet have data on actual conversion rates of users that clicked the ad (maybe serious users don't actually install the SDK, etc) but that's coming. If you're interested in this topic, you might also like my related post on A/B Testing.

Are you a technology entrepreneur with a startup focused on SDK adoption by developers? What tips do you have to share? Please leave them in the comments below.