Here are some tips to increase the effectiveness of your bulk SMS campaigns:

1. Target your audience: Make sure that you are sending the SMS to the right audience. Define your target audience, and segment your contact list according to demographics, location, interests, and behavior.
2. Personalize your messages: Address the recipient by name and make sure the message is relevant to them. Use their past behavior and preferences to tailor the message.
3. Keep it short and sweet: SMS messages have a limit of 160 characters. Keep your message concise and to the point. Use clear and simple language.
4. Offer value: Give your customers a reason to act on your message. Offer discounts, promotions, or exclusive content.
5. Timing is crucial: Send your messages at the right time when the customer is most likely to engage with them. Consider the time zone, the customer’s schedule, and their past behavior.
6. Use a clear call to action (CTA): Make it clear what the customer should do after reading the message. Use a strong and concise CTA that stands out from the rest of the message.
7. Test and optimize: Track the performance of your SMS campaigns and optimize them based on the results. Test different messages, CTAs, and timing to see what works best for your audience.