The people who keep talking about only marketing being a reason for Apple's success seem like haters! I've owned an iPhone 4 for 3 years now and don't recall seeing a single Apple commercial on TV, in the print media or other forms of advertising that influenced my decision to buy one. The only reason I picked it over any android device on the market was because it seemed like a better put together product than any Andrioid device out there at the time. I also have had no desire to switch to an Android device or any newer iterations of the iPhone as all the changes seem minimal and are certainly not features I would use everyday.
I too have an iPad at home along with an Android tablet and also iPhone and iPad are two of many development platforms for me at work and based on my own daily experience, there is not a single reason for me why I would prefer the iPad over an Android tablet. I still find those iOS devices utterly lacking and not very useful to me.
Also, Marketing does not equate to TV ads. There are several kinds of marketing strategies and Steve Jobs happened to make use of a lot of them effectively when he was alive. I know many people at work and outside who bought iPhones and iPads and most of them got them not because they thought or felt that they are better put together or because the feature set suits them, but because their friends thought its cool to own an iPhone or iPad and their friends thought so because their friends friends thought its cool. Many of these people don't even use their iPhone's beyond voice calls and texting. A very few use it for email and occasional browsing or casual gaming. Steve Jobs used to do this sort of brain washing to make his audience believe that owning an Apple product is cool just because, often without any realistic qualification of what makes it cool or what makes it a great product. Even lack of features was marketed as a great thing that Apple alone deliberately implemented. Even negative publicity of the competition or of technologies employed by or supported by their competition can be considered a marketing tool. Just look at negative publicity against Flash. Steve Jobs who is no way technically qualified to talk about either Flash or HTML5 did a negative publicity campaign against Flash and many of the things he said as part of it was pure junk. But, as a result of that campaign, there are a lot of people today who are also themselves not technically qualified to talk about either technology, but it doesn't stop them from thinking that supporting flash is uncool. I have come across the most extreme of idiots who thought that iOS is better android because it does not support Flash just because Steve Jobs proclaimed that flash is bad and there are also many in the iOS user community who think HMTL5 is exclusive to iOS without having a clue of what either technology is about. Believe me, a lot of Apple user community is made up of idiots who buy their gadgets mostly for the wrong reasons. There are even many people in US whose sole reason for buying iPhone over other alternatives is their misguided patriotism and their misguided belief that iPhone is an "All American" product made by an All American company, Techies who really understand technology or people who buy products based on their requirements make a very small fraction of this user community.
But then, it was also possible to attract and influence such people into becoming repeat customers mainly because of Steve Jobs charisma. I believe that most of Apples success can be attributed to Steve Jobs. Give him a dead cat and he would be able to sell it off for $500 after detaching its tail and then sell the tail as an additional accessory for another $200.
Apparently, this sort of strategy is not working well enough for Apple any longer now that Jobs is not around, so, that's why we see their desperation for trying to match the features, hardware and price points of their competition. Thankfully for Apple, Tim Cook does not have his head up his ass and he was quick enough to realize that marketing alone is not going to cut it any longer as it did for Steve Jobs. Just look at iOS7 and how many features and concepts it straight off borrowed from all the other mobile OS in existence. Many of these are things that Steve Jobs snickered at past and portrayed as negative aspects, but they are being added to their arsenal nevertheless. Its a great move and a move for the better that its catching up, but, personally I found iOS7 with my limited hands on to be a mess of inconsistencies currently. Maybe, things would get better better in couple more releases.