How long do Apple products last?

So I just bought a new Gold iPhone 5s and it's the first really nice up to date cell phone I've ever owned. I'm quite happy with the purchase and it's met and surpassed every expectation. It does everything and more. But someone asked why I just now got it when the new iPhone 6 apparently coming out in September. My question I suppose is, does apple keep updating and supplying features and accessories to its old obsolete phones and do they still remain fast and top of the line phones after about a year? And how durable are they?

The standard life of most smartphones is 1 1/2 - 2 years. Apple usually will make more internal changes with their updates on the software. If you have an iPhone 5 you will be fine for a couple more years. Each time Apple releases a new product, they also release a new software update that you can download on the product you already own. The main differences that are just for the new products are usually a better screen resolution or camera quality.

The phones themselves last. Provided you don't drop it and smash your screen.
but you will find after a month or two it will become slower, and start to have a few errors like loosing all your data, deleting your contacts etc etc.
you need to make sure you back up the phone regularly with itunes, if you don't, then you will loose everything when they phone plays up.
having said this, its not just apple phones that do this. All apple technology has a tendency to loose data, crash or not syncronise properly.

this is why apple constantly brings out new versions of phones and itunes, trying to fix errors with their systems without actually admitting to the public that they are haviing major issues.

youll notice they are the only company that has dozens of devices basically all the same released i a short period of time. My younger brother in the space of 1 and a half years has gone through 5 iphones, because they kept playing up under warrenty and the phone store had to keep replacing them.
i would never ever recommend anybody buying an apple.

You can use a new version like 5S for years, my old iphone I had for 3 years and it was still great when I bought 5S, the hardware improvements were so much better I really needed the upgrade but that was 3 years and 5S was way ahead. Plus iphones hold their value so well, that even when you sell your old version, you get alot of money back for it.

Smartphones will continue to work indefinitely, for years at least. Most people replace their smartphones long before they wear out. Apple products in particular are very well constructed and will last for years without any problem at all.

Waiting for the next phone doesn't make much sense, because there will always be a "next phone," and if you are constantly waiting for the latest thing, in the meantime you have nothing. It's better to just buy a phone and enjoy it. When it wears out, or when you get tired of it, you can buy another one. But always worrying about having the Latest Thing just keeps you from profiting from the phone in your hand. No matter what comes along in the future, your current phone will continue to work just as it always has.

Yes Apple still supports older iPhones after they have either been succeeded or discontinued.

For example, the original iPhone from 2007 was discontinued in 2008 but still got iOS updates until 2010 & supported most apps until 2011 when iOS 4.3 came out & basically became the minimum version required. For the record, Apple officially ended support for it in 2013.

As far as the iPhone 5s in particular, since Apple has switched to a 3 iPhone offered strategy now the 5s shouldn't be discontinued until 2016 & shouldn't stop getting iOS updates until 2019 (perhaps longer).

Right now, the 2010 iPhone 4 is still updated with the latest versions of iOS & of course the 2011 iPhone 4s, the 2012 iPhone 5 & the 2013 iPhone 5c & 5s.

As far as durability they would last long after you are either ready to or already have upgraded with proper care of course.