That makes sense, The first episode of series is there to sell you the series. They don't need to keep same quality after that because watcher's curiosity keeps them in.
Yea. Squid Girl's first episode was awesome! And 2nd one was funny but overall kinda drawl and had nothing to wow me. Of course I'll keep watch but it will not likely keep me attached if it stays at that quality. That's what happened when I watched madoka magica