Should I Open Source My Code?

I'm not talking about all of my code. Just part of it. I can see several benefits.

• I can release something to get me out of my 10-month-no-release hell
• Boost in motivation
• Early feedback from users/developers
• Good for my personal reputation
• Coding help from other users
• Can publicise my web application to all developers/users of the open source project
  
• Can lead the project in the direction I want it to go
• Reduce work load for this part of the website (not guaranteed)
• Reduce cost of this tool to $0. Competitors will (hopefully) struggle to keep up improving their propriety versions.
• Get to know developers that might want to help with my site.
• Lowering the risk of total failure. If my site fails, but this open source project succeeds, at least I've achieved something.
  

As for the draw-backs:

• This tool would be a particular selling point of the whole web application.
• Less profit?
  

This part of code that I'm talking about is JavaScript - a significant amount of JavaScript code. It's a large project in it's own right. I can see other open source projects wanting to use this as part of their applications.

If somebody did want to copy my web application, having this open source code would clearly help. However, after building a significant amount of my site I feel copying it would still be pretty difficult.

Clearly by writing this post I have convinced myself that going the open source route is best.