Nintendo has blamed "pipeline strain" for lagging online Wii performance, while promising improvements. Despite this, Super Smash Bros. Brawl has become the fastest selling Nintendo game in history, the company said.

"As with the launch of any online-enabled game, especially one as popular as Super Smash Bros. Brawl, everyone wants to play at once," said a Nintendo spokesperson in an email to GamePro on Monday. "This puts a strain on the pipeline."

With regards to an immediate remedy for ongoing lag and outages of Play With Anyone matches, the representative said, "We have seen improvements in online play performance every day since launch." Those seeking additional troubleshooting support while Nintendo ramps up its network can be found at support.nintendo.com or by calling 1-800-255-3700.

In a separate statement released today, Nintendo of America announced that Super Smash Bros. Brawl for Wii has become the fastest selling Nintendo game in history, selling more than 1.4 million copies after just one week of availability. More than 874,000 units were sold on launch day alone (March 9), the company said.