I definitely recommend customizing Linked In messages. At least in my experience, this is done all too rarely, making it fairly difficult to figure out why one has been connected to.
In my experience, recruiters are pretty eager to build a wide network, so I don't see any problem with your initial approach, the main point is:
- why did you want to connect?
- what are you looking to get out of the connection?'
Which you've covered. After that, keep it short and sweet (as you've done) - Linked In is built for very short messages, so writing anything longer than 2-3 sentences is not expected or required.
To take it one step further though...
Do some digging on the recruiter - know what kind of jobs they are touch with and why it's good to connect to this specific person. I, personally, don't find that the majority of my recruiter connections have been useful, so I'd recommend being fairly sure that the connection is worth while.
In communication, highlight the areas of work of this particular recruiter - either in the request or after the connectio - that you are particularly interested in... for example:
- I see you've done work with Company X. I'm particularly interested in companies like this which are (insert attributes)...
- I see you're connected to people A, B, C - they are colleagues of mine, and I have a great deal of personal respect for them. I have a similar skill set and am looking for...
I'd be inclined to do this after the initial link, to keep the communication small and streamlined.
The world of the recruiter seems to change weekly - so don't assume that because you connected a month ago and didn't hear anything more means that there's nothing to talk about. Keep a dialogue going and find a way to touch base weekly. Being linked on Linked In doesn't replace the need to check in and keep in contact.