Promotional campaign ROI depends less on which channel you default to and more on matching the channel to the audience and content type- see how WhatsApp, RCS, SMS, and Voice Broadcast each pull ahead on reach, engagement, and attention for different kinds of campaigns.
Trusted by 10,000+ businesses across India
Trusted by 10,000+ businesses across India
The WhatsApp Business API sends rich, catalog-style promotional messages- images, carousels, and CTA buttons- into a chat interface customers already use daily. What makes it distinct for marketing specifically is the opt-in requirement- an explicit checkbox, keyword, or QR-code opt-in is required before the first marketing template can be sent, and Meta enforces strict opt-out compliance that affects your sending quality rating.
RCS Business Messaging sends the same kind of rich cards, carousels, and CTA buttons as WhatsApp, natively inside Google Messages on Android. What makes it distinct for marketing is the opt-in rule- unlike WhatsApp, RCS doesn't require an explicit opt-in step within Google's content guidelines, so a promotional campaign can reach a Google-verified, branded inbox without that upfront friction.
Bulk SMS carries plain-text promotional content to any mobile number over the cellular network- no app, internet, or opt-in checkbox required for the message to be technically deliverable. What makes it distinct for marketing is that the promotional route is filtered by TRAI's DND registry- a number registered against promotional content simply won't receive it, which is a different mechanism from WhatsApp's or RCS's opt-in rules entirely.
Voice Broadcast (OBD) places an automated call to a list of numbers and plays the same pre-recorded promotional message to every recipient, with an optional "press 1" response element. What makes it distinct for marketing is that it's typically run as a consent-based, opt-in channel like SMS and WhatsApp, with TRAI/RTM telemarketer registration applying to promotional campaigns- and it earns its higher cost by being genuinely hard to ignore.
The same four channels look different once you narrow the lens to promotional campaigns specifically- opt-in rules, DND applicability, and cost per send at marketing-tier pricing all shift the calculus.
| Feature | Bulk SMS | RCS | Voice Broadcast | |
|---|---|---|---|---|
| Opt-In Requirement | Not required for the promotional route itself, but DND-filtered | ✅ Explicit opt-in required before any marketing template | Not required within Google's RCS content guidelines | Consent-based- promotional voice broadcast expects opt-in |
| Rich Media / CTA Support | ❌ Links only | ✅ Images, carousels, CTA buttons | ✅ Native rich cards, carousels, buttons | ❌ Audio only- optional press-1 IVR response |
| Verified Branding | ❌ Sender ID only | ✅ Green Tick (hard to obtain) | ✅ Google-verified badge | Caller ID only- no platform verification badge |
| DND / Regulatory Applicability | ✅ Promotional route filtered by TRAI's DND registry | Not DND-linked- governed by Meta opt-in & quality rating | Not DND-linked- governed by Google content guidelines | TRAI/RTM telemarketer registration applies to promo campaigns |
| Cost Per Send (Marketing Tier) | ~₹0.09-0.18 / SMS | ~₹0.79-0.91 / conversation | ~₹0.15-0.25 / message | ~₹0.28-0.48 / call |
| Best-For Campaign Type | Mass discount/sale blasts at the lowest cost per reach | Rich catalog showcases & retargeting an engaged audience | Branded rich-card promos at Android scale, no opt-in gate | Must-hear announcements- events, festivals, limited-time offers |
Opt-In Requirement
Rich Media / CTA Support
Verified Branding
DND / Regulatory Applicability
Cost Per Send (Marketing Tier)
Best-For Campaign Type
Cost per send only tells half the story- what matters for campaign ROI is cost per reach, and reach means something different on each channel. Bulk SMS marketing starts from approximately ₹0.09-0.18 per SMS, the lowest cost per reach of the four, ideal for high-volume mass announcements. RCS Marketing runs roughly ₹0.15-0.25 per message, adding rich cards and verified branding at a modest premium over SMS. WhatsApp Marketing is billed per conversation, around ₹0.79-0.91 per conversation, which pays for itself when a single conversation covers multiple follow-up messages to an engaged customer. Voice Broadcast costs the most per send, roughly ₹0.28-0.48 per call, but that cost buys near-certain attention rather than just delivery. At high volumes, the cheaper channels (SMS, RCS) compound their cost advantage across the full list; at smaller, targeted volumes, the ROI case for WhatsApp or Voice Broadcast strengthens because the fixed cost of richer engagement or higher attention is spread over fewer, more valuable contacts. See our Bulk SMS Pricing India and Voice Broadcast Pricing India pages for current rate cards before budgeting a campaign.
SMS has the widest raw reach at the lowest cost. WhatsApp and RCS have narrower but higher-engagement reach with richer content. Voice Broadcast has the highest cost but the highest attention-capture for promotions that genuinely need to be heard.
| Channel | Role | Why |
|---|---|---|
| Bulk SMS | Reach Leader | Widest raw reach at the lowest cost per send- every mobile phone, no app or opt-in gate for the message to land. |
| WhatsApp & RCS | Engagement Leader | Narrower reach than SMS, but rich media, carousels, and CTA buttons drive higher engagement per message sent. |
| Voice Broadcast | Attention Leader | Highest cost per send, but the highest attention-capture- a call is heard, not scrolled past, making it the pick for must-hear promotions. |
Bulk SMS
WhatsApp & RCS
Voice Broadcast
From ~₹0.09-0.18 per SMS, bulk SMS reaches every mobile number in your list regardless of smartphone, app, or internet access- the widest funnel for mass discount and sale announcements.
Rich cards, carousels, and tappable CTAs turn a promotional message into a browsable catalog- narrower reach than SMS, but a customer who opens it engages far deeper.
At ~₹0.28-0.48 per call, voice broadcast costs the most per send, but a ringing phone commands attention text can't- best reserved for announcements that genuinely need to be heard.
| Campaign Type | Recommended Channel(s) | Why |
|---|---|---|
| Mass discount / sale announcement | SMS + RCS at scale | Lowest cost per reach, DND-compliant on the SMS side, and delivered regardless of device or app. |
| Rich product showcase / catalog | WhatsApp + RCS | Native carousels, images, and CTA buttons let customers browse a catalog inside the message itself. |
| Event / festival announcement that needs to be heard | Voice Broadcast | Certainty the message was heard, not just delivered- suited to time-critical or unmissable news. |
| Retargeting an already-engaged audience | The deepest engagement medium for customers who already have the app active and have opted in. |
Mass discount / sale announcement
Rich product showcase / catalog
Event / festival announcement that needs to be heard
Retargeting an already-engaged audience
Most campaigns aren't single-channel in practice- a launch might use SMS or RCS for the mass announcement, WhatsApp for a follow-up catalog to engaged customers, and Voice Broadcast for a final reminder ahead of a deadline.
Trusted by 10,000+ businesses across India for campaign infrastructure that doesn't force a single-channel choice.
Manage WhatsApp, RCS, SMS, and Voice Broadcast campaigns from a single unified dashboard instead of four separate vendor logins.
Test creative and offers across channels and see delivery, engagement, and cost side by side in one report, not four.
DLT registration for SMS, Meta template approval for WhatsApp, Google RCS brand verification, and TRAI/RTM telemarketer registration for voice- all managed as part of onboarding.
Per-send cost drops automatically as your campaign volume grows, across all four channels, so scaling a promotion doesn't scale your rate card.
Talk to our experts about running WhatsApp, RCS, SMS, and Voice Broadcast together, with unified reporting and one integration.
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There's no single winner- it depends on what you're optimizing for. Bulk SMS delivers the lowest cost per reach, making it the best ROI channel for mass discount or sale announcements at volume. WhatsApp and RCS cost more per send but drive higher engagement through rich media, making them a better ROI pick for catalog showcases and retargeting. Voice Broadcast costs the most per send but wins on attention-capture for must-hear announcements. The right channel is the one matched to your campaign type, not the cheapest one in isolation.
Get Click Media runs WhatsApp, RCS, SMS, and Voice Broadcast on one platform- request a demo and we'll map out the right mix for your campaign.
