As the topic of the Ottoman Empire has recently been on mind as of late, I figure I would ask the idea: how big exactly (though within reason to keep things from getting ASBish) could the Ottoman Empire feasibly get? This need not necessarily mean direct annexation into the empire (though suggestions as to how would be preferred), perhaps even more along the line of vassal or puppet states. In other words, the goal is to give the Ottomans the biggest sphere of influence that could technically occur.
I'm not thinking of any actual specific time period either, so the sky's the limit.