Flashissue vs. Mailster Comparison Chart

Klaviyo is an all-in-one platform that makes it easy for B2C businesses grow by integrating marketing, analytics, and customer service in one solution. Powered by unified data and built-in AI, it's faster and easier than ever to create personalized, lasting customer relationships. Klaviyo unifies your customer profiles by capturing every event, and then lets you orchestrate your email marketing, SMS marketing, push notifications, WhatsApp, and RCS campaigns in one place. Klaviyo AI helps you build audiences, write copy, and optimize — so you can always send the right message at the right time, automatically. With real-time attribution and insights, you'll be able to make smarter, faster decisions that drive ROI. Trusted by more than 170,000 businesses, Klaviyo can grow your business while keeping operations simple and customer relationships strong.

Send messages your customers want to read (and act on). Attentive’s AI-powered SMS & email platform helps retail enterprises to e-commerce entrepreneurs engage customers and drive billions in revenue. We'll help you target the right audience and measure your most important metrics to optimize your marketing program. And with over 100 flexible integrations, you can seamlessly connect to the rest of your marketing stack. We partner with industry innovators in retail & e-comm, food & beverage, and media & entertainment. Attentive’s AI-powered SMS & email platform will double your ROI in just a few months. Learn more about our free 30-day trial.

GetResponse provides all-in-one marketing software that empowers marketers, solopreneurs, coaches, creators, and small business owners with affordable, easy-to-use tools for email marketing, marketing automation, and content monetization. With over 25 years of expertise, GetResponse goes beyond email with tools to help grow and engage audiences, create and sell courses, and turn ideas into income. It’s the go-to solution for building a personal brand, selling products and services, and fostering a loyal community.

HubSpot brings your marketing, sales, and service teams together on the same AI-powered customer platform. HubSpot's Customer Platform is not just a tool; it's the heartbeat of your business. Designed with passion and precision, our CRM stands out as the ultimate solution for empowering your team to build deeper customer relationships. It transforms the way you engage with your clients by offering a seamlessly integrated, all-in-one platform for sales, marketing, and customer service. With HubSpot's CRM, you gain unparalleled insights into your customer interactions, all organized in an intuitive, easy-to-navigate dashboard that promises to skyrocket your team's efficiency. Our platform is engineered to grow with you, offering scalable solutions that adapt to your evolving business needs. What's more, HubSpot's Customer Platform includes a robust free version, packed with essential features, making it the perfect choice for ambitious businesses of all sizes.

EngageBay is a simple, affordable, integrated, all-in-one marketing, sales and service automation platform with free CRM, built to grow small businesses and startups. The marketing automation suite helps you save time, nurture your audience and automate routine, manual tasks. With the free CRM and sales automation, you can organize all your email contacts, track deals, and the sales pipeline to grow your sales. Further, you can build meaningful customer relationships that stay for life. And finally, with the free live chat and helpdesk features, provide real-time assistance to convert visitors to happy customers. Track, prioritize, and solve customer support tickets in minutes.

Knak is the no-code platform that empowers self-sufficient marketing teams to create beautiful, on-brand emails and landing pages — without relying on developers or agencies. Built for speed and collaboration, Knak streamlines campaign production with modular templates, real-time editing, simple collaboration, and seamless integrations with leading MAPs like Adobe Marketo Engage, Salesforce Marketing Cloud, Oracle Eloqua, and more. Whether you're supporting global teams or launching fast-turn campaigns, Knak helps you go from brief to build in minutes—not weeks. Say goodbye to bottlenecks and hello to marketing agility.

WiseStamp is the leading email signature management tool. Unify your branding and boost your marketing with a company-wide email signature creation and management solution. Create professional email signatures in minutes with our award-winning signature generator, perfect for professionals and companies of all sizes. Achieve your goals by adding rich features like a CTA button, banner, video, disclaimer, scheduler, and more. WiseStamp auto embeds your signatures in your employees’ emails, whether it’s Gmail, Outlook, or any other platform, and gives you full control of all signatures from a simple dashboard.

Act! Advantage is a full front-office CRM solution with all-new functionality that unites sales, marketing, and customer management in one intuitive, affordable platform to help you stay organized, attract new customers, and turn relationships into results. Act! Advantage includes Interactive Quotes, Website Chat, Accounting Integration, Appointment Scheduling, Project Management, Web Forms, Online Surveys, and more, broadening Act!'s footprint across your entire front office, and reducing your need for costly, third-party tools. Additionally, you can select the perfect fit, cost-effective tier to meet your current needs with peace of mind knowing that Act! will grow with you. For 38 years, Act! has partnered with small and midsize businesses - listening, learning, and building alongside them and Act! Advantage is the culmination of nearly four decades of their feedback. Every feature is designed to reflect how today’s SMBs run their businesses.

Shape is purpose-built sales and marketing automation software that comes with pre-built features that can be configured for any business. The easy-to-use interface empowers your teams and consolidates all aspects of your business in one AI platform. Shape provides a collaborative space for your teams to stay aligned and efficient in everything they do, whether it's streamlining your sales pipeline, engaging more prospects with marketing sequences and digital ads, nurturing customer relationships, communicating seamlessly, or tracking projects. Start growing your revenue with Shape's suite of services today.

Convoso: The Best F 'ING Dialer for sales pros who mean business. Since 2006, Convoso has been flipping the script in the outbound sales, delivering an AI-powered sales platform that doesn't just help you grow—it helps you dominate. We’re not here to blend in; we’re here to stand out and help you do the same by driving profitability, connecting with more prospects, and crushing engagement at scale. And yeah, we’ve got compliance with TCPA and all the regs covered—so you can focus on what matters: closing deals. Convoso is trusted by thousands of customers across industries like insurance, financial services, solar, home services, BPOs, lead gen, and legal sectors. We’re not just another dialer. We’re the dialer built for closers.