WhatsApp: Texting Without the SMS Fee
I just installed WhatsApp on my iPhone 3GS. It’s a tiny app with a simple premise: it uses your internet connection (Wi-Fi or 3G) to send messages to your contacts. For those of us who grew up paying 10 cents per SMS (or more for international ones), this feels like a revolution.
Your Phone Number is Your ID
The brilliant thing about WhatsApp is the "frictionless" setup. You don't create a username or a password. Your phone number is your identity. It automatically scans your address book to see who else has the app installed. There’s no "adding friends" or "approving requests." It just works.
Under the Hood: Erlang and XMPP
From what I’ve read, the backend is built using Erlang, which is known for its incredible concurrency and reliability. They’re using a modified version of the XMPP (Jabber) protocol for the messaging itself.
// Why it's winning:
1. No login/password (uses phone number)
2. Uses data plan (bypasses SMS fees)
3. Status updates (the original 'killer feature')
4. Cross-platform (iPhone and soon Blackberry/Android)
Outlook
The carriers must be terrified. SMS has been a pure-profit "cash cow" for them for years, costing almost nothing to transmit but billed at a premium. WhatsApp is the first real threat to that model. As data plans become more common and smartphones become the norm, "texting" will stop being a carrier service and start being just another app. The days of the 160-character limit are numbered.
Aunimeda develops mobile applications for iOS and Android - from MVP to production-ready apps with full backend integration.
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