WhatsApp does not store messages on their servers. It's a clean passthrough from one device to the next. They only hold onto message until all clients in the group text or one-on-one text have received the sent message. So, if you have two clients using the same phone number, the system wouldn't know when it is able to delete the message. Right now the single phone receives the message and simply passes it up to the web browser. It's a simple solution that fits into their data model. They claim that they cannot get this working on iOS which prior to iOS 7 may have been true. However, on iOS 7 and above we can run code (even async network calls) when we receive a push notification so they should have been able to work with that API to produce similar results.
I believe you're wrong. This is how WhatsApp USED to work before they were acquired by Facebook. Remember how messages used to stay in the waiting (clock) state and you could delete them if the recipient wasn't online? Well now the first tick appears immediately because there's an intermediate server storing them for delivery and they can't be deleted from the client. It's similar to what Microsoft did to Skype.
I'm 100% sure that this wasn't the case. I'm not saying that there always was an intermediate server, but it definitely was before Facebook acquired them.
OK. I thought you were getting it confused with one of the message saving snapchat proxies (which then got hacked). But whatsapp is clearly not a replacement. snapchat may have failed to delete videos from the users device, but whatsapp doesn't even try.
WhatsApp used to even save snapshots of the database, for a week(?) I believe. In a SQLite DB. And deleted messages are not vacuumed. Recovering intentionally deleted messages off a user's phone was a trivial job. At least on the Android version.
I suspect that the reason is that WhatsApp wants to make sure that the person behind using the web client is really the person behind the number. This is same reason Whatsapp has no api. They don't want the bot problem that tinder has.
People think the value of Whatsapp is that it is so pervasive. That's a big part of the value, but so much of the value is that whatsapp knows who you really are. You might have a few twitter accounts, a couple of facebook accounts. But you have only _one_ whatsapp account.
There are phones here supporting two, three and even four SIM cards. People will do crazy stunts with multiple accounts for everything. Also there are whatsapp bots, they are just not available on github anymore due to DMCA takedowns. You can still google for yosup, coseme and others to get libraries that allow you to build bots, third-party clients and stuff.
Yes, I am familiar with libraries and considered building an app on the back of whatsapp until the DMCA takedowns. The fact that whatsapp is fighting against bots is part of the reason there is so little spam on whatsapp.
Yes, people do crazy thing with accounts, and in many parts of the world there are good reasons to have multiple SIMs. People will have 1 IG for sexy photos and another for their family, etc. But there is far less motivation to do that with whatsapp, line, viber, kik, etc. The reason for the difference in motivation is that your whatsapp messages are explicitly shared with individuals rather than with groups so there is no need to partition messages by accounts. The main reason for have two whatsapp accounts is the old joke about having two SIM cards: "one for your wife, and one for your girlfriend".
In Brazil (same place as the post author), some people do have many WhatsApp accounts. New number SIM cards cost equivalent to $3 dollars and dual SIM smartphones are very popular. Many people use these SIMs in a disposable way, changing them as telecoms change their prices.
That's true, but in my experience you have one at a time.
For south east asia it's normal to have one SIM for your local number and one SIM for your international number. Or just SIMs for different networks so that you can get free calls to friends who are the same network. But even then people usually have only one whatapp account at a time.
I believe the webapp retrieves your message history from the phone in real time, and Whatsapp does not store messages on their servers once they have been delivered.
What? Is this true? I can't think of a reason why their devs would ever need the users phone to be online.