Creating lots of small apps / spamming is not the way to go. Doing your best to create something great will be a lot more fun / challenging. I've only created 2 apps so far, and I'm doing pretty well. If I had spent the time creating 20 different apps instead, I am pretty sure I would not be close to being successful.
Another advantage of going quality over quantity is that people will seek you out. Over the past year I've been able to augment my app store income with other opportunities that have only resulted from the fact that my apps have been at the top of the app store. I'm not really allowed to say more than that due to NDA, but I've been offered some very lucrative business opportunities. So, looking at app store as just a profit center is the wrong way to look at it. You need to look at YOURSELF as the investment. Challenge and push yourself to create something great, and great opportunities will come. Even if you don't succeed per say, you can always get a better job down the road if you can point back to a great app that failed to sell than 25 crapps.
My 2 cents.
This should be a sticky.
__________________
Yes, I am that man from Nantucket
what is your traffic volume & on which geography is it coming from???your earnings will be heavily dependent on that…it is a volume game so make sure the volume is high…
I'm relatively new to the App Store, and can't really give any advice on that front, instead I'm here trying to learn from you lot. Anyway...
I think a good strategy is to also look for something that people like (and ideally that you like too), whereby you can see a lot of room for improvement. Then just make an improved version of it. This is what Facebook, Angry Birds, and just about everything successful is.
If you have a product that nothing else closely rivals it, then you don't need to waste lots of energy making it squeaky polished with lots of levels/worlds/characters etc. You just need to do enough for people to enjoy it. Once you have something successful. When you release the sequel you can pack all of that, i.e. you can give it the Hollywood makeover. It's easy to look at successful games like Angry Birds Rio, Ragdoll Blaster 2, or even Facebook and say "Gee, look at that, that's why it's successful.", but in reality the first versions of these were far more simpler, less glamourous, and they were what made the success. The sequels and version updates just ride on the back of that initial success.
I come from a programmer background, and thus still learning the biz/advertising side of software dev.