I compose mainly for myself too, but that doesn't mean I don't want it performed or to be heard by others. Just writing down a piece can also be fulfilling, but never quite as much as getting an actual physical sound out of it, so I do try to get everything major I write performed. (That doesn't apply when I'm just doing something for a little non-serious exercise or something.)
The last few years I've mainly composed on commission, i.e. I wrote pieces of a specified duration for a specified instrumentation with a fixed deadline. This has the great advantage that you always get a performance, sometimes even a really good one or with a large ensemble (say, an amateur orchestra). And it also means that you are pressed into writing things that lay outside the scope of what you'd do otherwise, which forces you to expand your musical thinking into new areas, which can be quite exciting when it works.
But after the last such piece I've now finally started with a piece I wrote without any outside reason whatsoever. It's a piece for three pianos and the only reason I'm writing it is because I feel like it (and have wanted to write for that instrumentation for a couple of years already). I have no clue if or when it will be performed (I'm confident that I will get a performance though), or when it will be finished, and I'm
loving it. It makes such a great change to write a piece for once where I can do entirely whatever I feel like, make it as long or short as I want and take my time, maybe three months, maybe half a year, maybe two years, maybe even longer, who knows.
I think all of these approaches have their merit. And I don't think you -must- get a performance, even though for me, I seem to need a performance to be able to draw a final line under the piece, to make it truly finished. Plus, I just love hearing my stuff performed. I'm vain like that
