Good luck to all you daters today Mercury, Scrazy and Snape. Sorry if I've forgotten anyone. This is a great day, very well-starred, honestly, so I know you are all going to have the best time.
Sparks . . . well, there is a huge difference between pure animal lust - maybe that's the fireworks - and the spark. The thing is, I don't think the spark is purely a physical thing. That comes into it, sure, but it needs to work on different levels and so it's not something you can be sure of straight away. There needs to be some level of attraction there at the start, but on the first date people often behave a bit, well, differently to normal, particularly if they are nervous or trying to make a good impression. That's not the real person, and it's only when you start to get to know them that you can see if the spark is there.
Fireworks - well, fireworks are short term. Fireworks aren't sustainable. Fireworks burn out quickly and leave nothing there to take their place. If you're really after fireworks and not the spark, then maybe short-term relationships are the best place to find them. The spark can last and last and it's what makes relationships worthwhile.
The alternative to fireworks isn't meh.