Yahoo! is holding a press conference on Monday in New York at 5 p.m. EDT, presumably to discuss the merger, though no official details have been announced. TheStreet will be attending the press conference live. I recently suggested three places for Mayer to consider spending Yahoo!'s cash, including Zynga ( ZNGA ), Yelp ( YELP ) and Pinterest. Those companies are poised to produce significantly more in annual revenue than Tumblr, though all three would've come at a higher cost than the $1.1 billion deal for Tumblr. Yahoo! is chasing a younger audience here, the 18-34 age group that primarily uses Tumblr. For now, it's been reported that Yahoo! will give Karp and his team independence, except for some back-end stuff, and expanded opportunities for distribution. That's the right idea until Mayer, Karp and their respective teams figure out how to best monetize Tumblr's vast user base in a meaningful way. -- Written by Chris Ciaccia at TheStreet