In the wake of Yahoo's announcement on Monday that it's snapping up Tumblr for $1.1 billion, the attention has shifted to other private technology companies that could be next. (A little horn-tooting: After Facebook bought Instagram more than one year ago for $1 billion, I predicted that Tumblr would be the next big acquisition in this new media space.)
So what makes a company a hot acquisition target? While these types of buys don't need to be profitable—as we saw with Tumblr—they do need to have massive reach, particularly with a younger demographic. They also need to boast a mobile component—that's where users are heading. And they're almost necessarily social—everything needs to be.
(Read More: Tumblr Deal Gives Yahoo Social, Mobile Boost)
With that in mind, here are eight other potential takeover targets in the media and technology sectors:
Twitter is the holy grail of powerful start-ups, with 200 million active users, global reach, and ads that are designed to be engaging and relevant. The service is also native to mobile, leaving it well-positioned as people spend more time on mobile devices and away from their desktop computers. There's been speculation that any number of Internet giants should buy Twitter, but with a $10 billion valuation, some say it an initial public offering may be more likely.
Foursquare's mobile, social, location-based service helps people connect with friends and find restaurants or hot spots nearby. With over 30 million people checking in millions of times each day, its valuation was $600 million last year, the most recent estimate available.
Mobile messaging app Whatsapp boasts that its hundreds of millions of users, and as many as 2 billion messages per day, make it bigger than Twitter. It's been a rumored acquisition target for both Facebook and Google,with a price tag of about $1 billion.
Social, location-based traffic service Waze drew acquisition interest from Apple at the beginning of the year and more recently from Facebook. Its price tag is also reportedly in the one-billion-dollar range. Waze's appeal: It has 36 million drivers submitting reports to improve traffic information.
Hulu, which is back on the auction block for the second time in two years, has drawn interest from Yahoo and Amazon, as well as Guggenheim Digital Media, and Chernin Group. Its price will hinge on the longevity and exclusivity of its deals.
Yahoo tried to buy video-sharing site DailyMotion earlier this year. The appeal: more than 112 million unique monthly visitors and half-a-billion video views. The challenge: It's owned by France Telecom. Yahoo dropped its bid after the French government objected to France Telecom selling more than half the company.
For visual content, Pinterest has more than 48 million unique visitors sharing photos, products and ideas. This week, the company took a big step to work with brands to make it easier to click and make a purchase. In February the company raised a $200 million round of funding that values the company at $2.5 billion.
Social news website Reddit is the go-to for trending topics. Its 70 million monthly visitors vote on which stories are important, and can comment on every one of them. The service also allows community members to add features and tweak the system. It raised about $1 million in January at a reported $400-million valuation.
—By CNBC's Julia Boorstin. Follow her on Twitter: @JBoorstin