(CNN) -- Talk about being a victim of your own success.
Among several new initiatives announced by Marvel Entertainment at the South by Southwest Interactive Festival was a two-day giveaway of 700 issues of classic Marvel No. 1 issues via their app.
The adventures, new and old, of the X-Men, Spider-Man and the Avengers would be available free, and the first issues would make it easier for new readers to follow.
It was an unprecedented offer in the world of digital comics. But perhaps it was one that its technology partner, Comixology, was unprepared for: The servers crashed.
One day after the freebies were announced at Marvel's SXSW panel in Austin, Texas, it was put to a halt -- at least temporarily -- by Comixology. The problem: too much interest.
"We expected a high degree of excitement for the Marvel initiative -- and had believed ourselves prepared -- but unfortunately we became overwhelmed by the immense response," admitted Comixology's CEO and co-founder, David Steinberger.
"We're still struggling to keep our systems up."
Steinberger added, "We don't like letting you down. Our teams are working around the clock to resolve these issues so that you can have the experience you've come to expect."
He said the promotion would be "pausing for the time being."
Comics readers were told to post their e-mail addresses on a form to be notified when the offer would be back up and running.
Marvel posted a statement to its website: "Marvel fans assembled in record numbers to take advantage of the landmark Marvel #1 digital comics sale! The demand has been so overwhelmingly positive, in fact, that a number of technical issues have arisen with our technology partner in getting the more than 700 free issues to each of you. When we have further updates from our partner, we will share them."
To that end, Marvel has increased its presence at SXSW, this year announcing products such as the weekly Infinite Comics, which are specifically designed with the digital reader in mind, and Project Gamma, which adds audio to the digital reading experience.