What is SMS vs MMS?

SMS (Short Message Service) and MMS (Multimedia Messaging Service) are the two standard messaging formats available on virtually every mobile phone. SMS handles plain text messages up to 160 characters. MMS extends that capability to include images, GIFs, video, audio, and longer text content.

SMS was introduced in 1992 and remains the most universally supported messaging format. Every phone with a cellular connection can send and receive SMS — no app downloads, no internet connection required. MMS arrived in the early 2000s and requires a data connection to transmit media files.

For ecommerce brands using text messaging as a marketing and sales channel, the choice between SMS and MMS affects message cost, deliverability, engagement, and conversion. A third format — RCS (Rich Communication Services) — is emerging as the next evolution, adding interactive buttons, carousels, and branded sender profiles to the text messaging experience.

SMS messages travel through the cellular network as plain text. If a message exceeds 160 characters, the carrier splits it into multiple segments (each billed separately). The recipient's phone reassembles the segments into a single message. Long SMS messages of 300+ characters may cost 2-3x a standard message in credits.

MMS messages transmit media files through a data connection alongside the text. The media is typically compressed to stay under carrier size limits (300KB-600KB for most US carriers). MMS messages cost more to send than SMS — typically 2-3x per message — but support product images, branded graphics, and visual content that plain text cannot convey.

RCS messages use the data connection like MMS but add interactive elements: tappable buttons, product carousels, read receipts, typing indicators, and verified brand profiles with logos. RCS requires carrier and device support (widely available on Android, coming to iPhone). For recipients without RCS support, messages fall back to SMS or MMS automatically.

Text-to-buy works across all three formats. With SMS, customers reply with text to purchase. With MMS, brands can include product images before the reply-to-buy prompt. With RCS, customers can tap a "Buy Now" button directly in the message — combining visual merchandising with one-tap purchasing.

The format you choose affects both cost and performance. SMS is the most affordable and universally delivered, making it ideal for transactional messages, reorder prompts, and reply-to-buy campaigns where the subscriber already knows the product. MMS drives higher engagement for new product launches and drops where a visual makes the difference — brands report 15-20% higher click rates on MMS vs SMS for promotional campaigns.

For text-to-buy commerce specifically, SMS is often the better choice. The purchase happens through the reply, not through a link or image — so the visual element of MMS adds cost without necessarily adding conversion. Where MMS shines is the first message in a drop sequence: showing the product, building desire, then following with a reply-to-buy prompt.

RCS represents the next leap for SMS commerce. Instead of choosing between cheap-but-plain (SMS) and visual-but-expensive (MMS), RCS delivers rich media with interactive purchase buttons at SMS-like costs. Brands using AudienceTap get RCS with automatic SMS fallback — reaching customers on the richest format their device supports without manually managing format selection.