-Following from the previous point, having a large portfolio of games will help because you can cross advertise all you games within each game. That way if one of your games is successful, you can try to leverage that success by directing traffic to the rest of your portfolio.
excellent point here... I always see Blizzard doing it and always thought it was genius.
-I read around the place that one important thing we should all do is create an email subscription list
another great point, I think any pr is good pr. But people do hate this step.
-As a general rule of thumb, everything is harder when publishing on iOS. The pipeline has more steps, the approval process is a nightmare etc. BUT as a mobile dev you absolutely MUST target iOS. Its a non-negotiable. I would go so far as to say that you should make iOS your priority 1. It's where the money is. iOS represents the high end, wealthy part of the market.
I honestly am totally intimidated by iOS. I worked on a team years ago and we made mobile apps, but I was just a designer and sound designer, I wasn't doing any really technical. It was such a pain...just no good, the process to just test it was a headache. And when we finally released the same thing happened, we were featured and got tons of action, then we weren't and everything stopped - like nothing. Then a new version of iOS came out and broke the game, we lost our programmer and it was over.