Marketing.

How about all of the above and a little luck!

Here is another aspect of a success story...

http://money.cnn.com/2017/06/27/tech...ory/index.html

The brand is the MAIN factor. Then comes the outer finish. The models do not differ much on the first view. And all of them look the same when theres a silicon case around. And honestly, who cares about hardware other than camera, number of cores and clock frequency?

I think for the mass, the phones which are cheap to get from your provider as bundle are the most successful. If the phone is advertised well you'll probably pay some extra money.

For me it was the hardware keyboard in the past. Now it's the OS, even if it's jailed in a poor device. But....you can ssh on it

What makes a phone a success?
All the things the above "Brains" have mentioned....
and one other thing...

What makes a phone a success? ...
why....the Production..
the making of the phone ...physically...
is a success...unto itself.
everything after that...
the os ..software..support..etc..
is all the follow-through.

Many phones never get near to production...

I could name at least one or two off the top of my head...

Even better, apps were never even the intention! They simply turned out to be pretty good at generating money out of thin air, and the rest is history.

Hardware keyboard (especially if it is comfortable to type on) and Linux-ish OS (webOS-LunaOS, Sailfish, Maemo, Ubuntu...; or ability to multiboot at the very least). Unique design is a plus (BlackBerry Passport looks very interesting, because of square display and touch-keyboard), locked firmware is a minus. Oh, and given current 2G-off crisis, I want "concealed" USB ports so that cellular connectivity would be not hardwired into the device, but put into a replaceable USB stick. Would make the device much thicker, probably, especially with 4+ concealed USB ports (don't want sticks to be conspicuous / easy to lose / getting in the way of holding the device and using it).

Thank you. Best regards.
~~~~~~~~~~~~~~~~~
Per aspera ad astra...

That is a very good idea; having a device with internal slots for USB sticks makes a lot of sense from both security and extendability viewpoint; I had thought about this myself before. You could stick in not only modems but all range of other USB-niceties!

However there are quite a few practical problems with that approach; as you say it would make a device lot thicker, I'd say it is only practical in almost-laptop sized devices.
Another mechanical constraint is how large a space to reserve for each stick; USB devices vary in size a fair lot. Also in case of modem-type sticks, you need to design the enclosure so that the antennas get decent radiating environment.
There is also the fact that separate devices on USB bus consume more power than integrated solutions, this also suggests that the solution is only usable on larger devices with high-capacity batteries.

The problem is that if you can write a bash script or solder you are way out in the <1% of tech users, you are not a market you are a market breaker.
While the engineering department at a few places has gotten out of control (ie. Nokia Maemo group, Sharp Zaurus, etc)and made something THEY(also 1%ers) think is kickass, this is not what the market wants.
So first who is this apparently anti-user restrained awesomeness market?
Not users, but the mobile telephone companies who farm the users for their money, these companies also get some coercion for backdoors and illicit access from the security services of many nation states, even/especially those of alleged democracies.
Did you think that those 'free' phone for a year or so on contract were a gift? I wonder if even 10% of people actually go out and buy the phone they want vs taking the 'gift' of a new phone from a predatory mobile network.
When you create an uncontrolled hacking friendly device that enables users to do something simple and obvious like USB/Bluetooth tether it is reducing the value of that customer who is to be squeezed to the max for profits.
I would love a phone with a true 100% FOSS GNU/Linux OS including drivers, I want the hacker buss or USB ports even if just several USB power/data pads or pins and an internal hub to hack awesomeness into my pocked comm and computer device.
Maybe we can influence someone like Bunny Huang who knows Senzhen China and cares not only for the prolific hardware hacks of Senzhen market stalls but also the western wing of our movement which has made a cult around also sharing those improvements as embodied by the GPL, staving off a premature post-purchase EOL for good hardware which falls behind updated APIs and security holes. Produced in Senzhen where manufacturing is cheap and clones of successful hardware drive the market a great device with community OS support will get all of the inexpensive hardware support we need in exchange for everyone from corporate engineers to anonymous hungry geeks hacking both the hardware design and software side from duct taped old Linux laptops and cantenna'ed wifi.
All I ask is that when that line of epic devices begin to build I want a serial line out and a POCSAG pager service module so my phone
can be radio silent until I choose to activate out signalling services. I want no shared connection between the CPU or memory and the untrusted modular cellular modem. I want all of the hackability to be aimed in my direction, not a menu of vulnerability for others from black hats, to greedy corporations, even antidemocratic government agencies to use against me and the surrounding population.

This varies from country to country.

In finland for example it was previously (when 2G was the hot thing) illegal to sell operator-locked devices, hence operators did not offer "free" or cheap devices but the competition between operators and independent vendors was true. People always paid the full price on a device and bought a network contract separately.

For 3G the rules were relaxed a bit, on the assumption that it would help 3G to gain faster marker penentration; it was possible to bundle a phone with a service, but operators still had to give you the same price if you wanted to buy just the device which kept the prices from diving to the bottom.

I think this system is pretty fair and makes the pricing of devices and services more transparent; the end-user benefits from competition and freedom of choice.

I am fairly surprised that some countries that are supposed to be major forerunners of freedom do allow for monopolistic practises from operators...