Dish Network’s Sling TV online pay-TV service launched last month, but it’s still something of a work in progress — as it gears up for coming competition from Sony and potentially Apple.

The satcaster’s over-the-top service, priced starting at $20 per month, continues to add new features and networks, aiming to sweeten the pot for consumers who want a cheaper alternative to a full-blown cable package.

Sling TV is now available on Microsoft’s Xbox One, adding to its existing lineup that includes Roku, Android and iOS devices, and Macs and PCs.

In addition, Sling TV will add four A+E Networks channels — A&E, History, H2 and Lifetime — by the end of March as part of the core $20 package. That will bring it to 20 networks total, including ESPN, ESPN2, AMC, TNT, TBS, Food Network, HGTV, Travel Channel, IFC, El Rey, Adult Swim, Cartoon Network, ABC Family, Disney Channel, CNN and Galavision.

However, while Sling TV has reportedly signed up more than 100,000 users since its Feb. 9 launch, it’s still unclear how big the market is for such OTT services.

Analysts estimate there are roughly 10 million U.S. homes with broadband but no pay TV, and millions of those may not be interested even in a skinnier, lower-priced package of channels. And as of early February, at any rate, Sling TV had very low awareness among consumers, many of whom also confused the service with Slingbox.

At the same time, the fight for subs is fierce in the pay-TV sector, as traditional providers keep losing ground. Sling TV already competes with existing pay-TV ops, including to an extent Dish’s own satellite services. Now, it will face several new competitors with the same OTT model. Sony this spring is set to debut the PlayStation Vue service, aimed at users of its gaming consoles, and Apple is now reportedly trying to assemble a stripped-down Internet TV bundle to launch in the fall.

To promote Sling TV’s launch on Xbox, Dish and Microsoft are offering current Xbox Live members with an Xbox One one month of Sling TV free. Additionally, the first 5,000 customers who purchase an Xbox One between March 17-22 will receive three free months of Sling TV service.

Meanwhile, Sling TV has split its originally offered “News & Info Extra” add-on package, priced at $5 per month, into two tiers (both $5 monthly). The two new packages are “Lifestyle Extra,” with TruTV, Cooking Channel, DIY and WE tv, and FYI and LMN to be added later; and “World News Extra” with Bloomberg TV, HLN, Euro News, France 24, NDTV 24/7, News 18 and Russia Today.

Sling TV said it plans to grandfather existing “News & Info Extra” subscribers into both the “Lifestyle Extra” and “World News Extra” for a total of $5 per month. The company noted that the “Lifestyle Extra” tier, with the inclusion of Turner’s TruTV, provides access to NCAA March Madness games across multiple devices.