A man looks at his iPad while sitting in a cafe in central BeijingBy Malathi Nayak SAN FRANCISCO (Reuters) – The annual no-holds-barred Christmas vacation slugfest between cellular game developers has a brand new twist this 12 months: advertising and marketing and user-acquisition prices will seemingly hit an all-time excessive and surpass any revenue earned over the festive season. The cost of getting new customers through paid-for click-thru commercials on cell phone apps and Fb is skyrocketing. Trade executives say there are extra mobile games than ever intending to grow to be the next "Candy Crush Saga" or "Conflict of Clans" and developers are spending to get there. That poses a problem for heaps of builders starting from San Francisco-based totally Glu Mobile to impartial studios hoping to follow in the footsteps of outfits like Supercell and King, analysts say.