God lacks and needs nothing. God has been perfectly satisfied and joyful in his own nature from all eternity. God is perfect, and God needing something implies insufficiency and imperfection.
That being said, God might be obligated (to himself) to express his glory fully, and, in a certain sense, that requires spectators. If a tree falls in a forest and there is no one to hear, does it make a sound? What would it mean if God expressed his glory with the greatest symphony or the greatest universe, if there was no-one to see it but him? In the same way, glory is not completefull, in some sense, without someone else to see and enjoy it. This require God to create
(No, minimallyperhaps God is the only spectator that matters. Still, spectatorsit does seem a logical step for an infinitely great God to express his glory to creatures.)
Once God creates people, they would be obligated to acknowledge this glory, and to do so often and with joy (as is fitting and honest). And God, if he was good, would make himself known to them, as he is the highest and only good that exists.
Along the lines of what Caleb said, for a man to be self-centered is an evil, because it robs God (the only one who actually deserves worship) of worship. But for God to promote himself is a virtue, because he is ultimately what is best for people.
He is best for people because he is infinitely glorious, because nothing else has any value besides him, and because whatever has value has value only because of him. It is the ultimate good to be united to the infinitely glorious God. For godGod not to promote his own interests would be the cruelest crime of all!