RIM recently paid $8.3M to buy the once highly buzz-worthy Dash Navigation. Dash was a GPS-masquerading-as-in-car-software-platform company. And, you know, there is no better way to instantly sound bigger than to say, “we’re a platform for…”

I personally loved the Dash as a product, but just was never quite sure about the whole platform focus. There are two problems with the “platform” approach, one is that platforms are hard - you need to both create a killer product and convince others to build killer products for you. The second is that the tactic is often more about ego and makes your life harder for little benefit, no matter how instantly sexy and “big” a new platform sounds.

Dash Navigation could have built on a pre-existing platform, as Stacey over at GigaOm points out. Slacker radio (which I love) and Kindle have similar issues. Do their separate devices warrant an entirely new platform or is being on the iPhone/Android/etc close enough?

We went through this several times at Ambient Devices, where we got regular questions about whether we should just be embedded in cell phones and laptops - a tack that our major competitor Microsoft Spot took before they ultimately died. Despite the ill fate of Spot as part of another platform, which I chalk up to execution, I’m still not sure the separate device (new platform) was the right answer.

Over in social gaming land, I was talking with James Currier last week and he made an empassioned point about building inside of existing social networks. Why build a new platform from scratch when your customers are already coming back to Facebook (retention), already have their friends there (acquisition), and spend more time there (engagement).

Is your idea really worth trying to be one of the 10 URLs an average person visits in a day? Is your idea really worth being one of the three devices an average person purchases in a year? If not that doesn’t mean it is a bad idea, most $100m+ revenue companies do so without creating a platform - it just means you need to look for the best ecosystem to exist in.