One of Sling TV's biggest selling points was that it offered ESPN and Turner Sports in its $20 per month web TV bundle, and last night, the service failed during one of the most-watched sporting events of the year: the March Madness semi-finals. The Duke vs. Michigan State and Wisconsin vs. Kentucky games brought in a surge of viewers all at once, and for some people trying to watch Turner's broadcast, Sling just stopped working.

Had high hopes for @Sling TV, but it was completely crappy for this basketball game. Shame, shame. — Andrew (@thecragfox) April 5, 2015

I'm cancelling my @Sling account can't even keep a solid connection trying to watch the badger game thanks for the shitty TV service. — KoR x BdLckKd (@bdlckkd) April 5, 2015

#slingtv is a major fail for NCAA finals — DennisRobinson (@DennisRobinson) April 5, 2015

My @sling TV experiment appears to be over. I really wanted this to work. So who is winning? pic.twitter.com/SVX9BC0kHu — Kendal Killian (@KendalKillian) April 5, 2015

Sling's service cut in and out throughout the games, if it worked at all, Recode reports. The errors suggest Sling wasn't expecting such a large number of Final Four viewers, but it definitely should have. The service reportedly had 100,000 sign-ups in its first month, and March Madness is a hugely popular, billion-dollar event. In 2014, the NCAA semi-finals were the most-viewed college sports event in cable TV history, and this year was no different. Including conventional TV viewership, last night's Wisconsin/Kentucky game was the most-viewed Final Four game in the last 22 years, Recode reports.

We're sorry some basketball fans saw errors tonight due to extreme sign-ups and streaming. Engineers rebalanced load across network partners — Sling Answers (@slinganswers) April 5, 2015

Sling apologized for the errors on Twitter, but this is a common problem with internet television. Despite the growing popularity of cord-cutting, web TV is still often unstable and unpredictable, especially when it comes to big live events. ABC's recent livestream of The Oscars kept cutting to a screening of The Social Network and episodes of Jeopardy.

In spite of its problems, web television still seems to be the inevitable future of TV. Apple is reportedly in talks to build its own internet TV service and HBO plans to launch a standalone HBO Go subscription later this year. Longtime cable users making the switch will have to get used to bandwidth problems and router issues that still come with the territory.