Toys 'R' Us opening temporary holiday stores

You may see a lot more of Toys 'R' Us at the mall, as the toy store giant opens up 600 smaller, temporary "pop-up stores" in vacant mall spaces just in time for the holiday season.

By doing so, the retailer is doubling the number of its U.S. stores and taking advantage of lower rents. Last year it opened 90 temporary Toys 'R' Us Express stores, a move that bolstered its holiday sales. Toys 'R' Us also plans to open holiday sections in its 260 Babies 'R' Us locations.

The pop-up store has become a trend since the recession began in December 2007. Sometimes the stores last a few days for a special event, but most last a few months and tend to be based around the late October-January holiday season.

The temporary stores also help fill otherwise empty stores. The national vacancy rate for malls in the U.S. was 9 percent in the second quarter of this year, up from a low of 5.1 percent in the second quarter of 2005, according to Reis.