3 Social Media Startups to Watch From SXSW 2013The 'next big thing' in social media might not have debuted this week, but SXSW 2013 was not without noteworthy startups.

If you've been waiting to read about "the next big thing" insocial mediaor tech to come out ofSouth by Southwest (SXSW) Interactivethis year, don't hold your breath. We've canvassed the festival and feel confident reporting that a powerhouse along the lines of Twitter or Foursquare -- which launched here in previous years -- is not in Austin right now.

But there are interesting tech startups that are generating some buzz. As the interactive portion of SXSW winds down, here's a look at three companies that we found most interesting:

1. Speakerfy:A social way to listen to music across devices.
The founders ofSpeakerfycan count former NBA center Shaq among their biggest fans (and not just because of he's over seven feet tall). Speakerfy, an app that lets users wirelessly sync music between different internet-connected devices, was one of two winners of the "Pitch Shaq" contest. Registered SXSW attendees submitted 15-second pitches about their startups in hopes of winning some face time and possibly a monetary investment from the sports star.

Say, for instance, you were on the beach with friends but were without an appropriate audio system. With Speakerfy, you could sync up everyone's smartphones and tablets and iPods to play your music -- broadcast through the speakers on those devices -- all at the same time. It also allows users to link their playlists with other users. Speakerfy is available (free) on iOS devices and is expected on Android and Windows phones soon.

2. Hyperactivate: Smart, social promotions for brands.
Started three years ago,Hyperactivate's"Hashtagart" application creates a real-time mosaic of avatar images collected from social networks every time a fan publishes a status with a client's marketing message.

Having worked with brands likeVerizon,M&M'sandMajor League Baseball, Hyperactivate says its mosaics usually generate 10,000 to 50,000 messages from fans and followers, which in turn have directed as many as 500,000 visitors to a brand's landing page. People are encouraged to share a brand's marketing message in order to be included in the interactive mosaic product.

Additionally, Hyperactive's platform is able to measure the number of clicks and activations each social media message associated with a promotion generates, the company says. Fun and, ideally, smart marketing.

3. LeadRocket: A social tool for salespeople.
The goal atLeadRocketis to improve the way business owners and their sales representatives communicate with clients over social media. The LeadRocket platform allows business users to launch and manage sales interactions over social media by listening for feedback, monitoring clicks and counting page views for pages on their site that originated from those social media posts.

Basically, it lets you know exactly when a customer engages with your tweet or Facebook post and tells you if they clicked on it and how many pages they looked at. For sales people, it can be especially useful for knowing when to follow up and what topics among the content shared interests them most.

LeadRocket offers atiered pricing system. Accounts include basic (free), premium ($19.99) and team (pricing varies).