Signal has been around for several years and this week they introduced a freemium model to promote their cross-channel marketing campaign software. You can sign up for a free account that entitles you to send 5,000 emails or 1,000 text messages per month for up to 500 subscribers and paid accounts start at $30 a month for unlimited messages. That is a pretty good deal and something to consider if you haven't yet used any of these services, or are looking to switch from a more expensive one.

Signal can be used to manage email marketing campaigns, similar to Constant Contact, MailChimp and Eloqua, among many others. But it also adds in social marketing and mobile features, such as the ability to add QR codes and URL shortening services too.

You can build your mailing list with four different methods: a Web form, importing a spreadsheet of contacts, using their API or texting to a short code. They offer three different types of pre-set marketing campaigns: a trivia game, polls or sweepstakes. And there are a lot of other tasks you can do as well, including scheduling regular email mass-mailings, surveys, and creating live chat sessions.

You can see the variety of tools that they offer from the screenshot below:

Each step of the way they offer lots of online help and video tutorials to walk you through the process. The site is attractively designed and it seems straightforward to use.