Open-sourcing your project, pros and cons

Hi all,

I was wondering what were your thoughts on open sourcing your work, or part of it.

Context
My app is MediaTag, an easy & flexible way to organize anything digital. I have no plan to open source all of it, but it works with an extension that requires fairly high permissions, at least the kind that makes me think twice when it is from someone I don't know.

Current Solution

1. In order to reassure users, I've decided to open source this extension. The code is visible here at https://github.com/mediatag/extensions. So it is not that the code in itself is interesting, but its presence should help raise trust.
2. I've also extracted a basic version of the extension, which has less feature, but does not require any permission at all. So users who do not trust me might find it easier to start with that.

Pros & Cons:

Pros

• As mentioned above it reassures customers.

Cons

• It reveals non public APIs.
• It may give ideas to competitors.
• It may reveal bugs (gasp!)

So at the moment, there seems to be more negative aspects. But maybe I am seeing it the wrong way?

What do you guys think? Has any of you experience in open-sourcing his work?