Jefferies analyst Alex Giaimo said his firm's recent survey of 1,000 U.S. smart phone owners showed that nearly 90% of them play mobile games and about 41% of those survey said their time spent playing mobile games has increased over the last 12 months. The survey results support his confidence that mobile will remain the fastest growing sub-segment within gaming and his view that Activision Blizzard (ATVI) can build a $1B mobile business, ex-King, by 2023. The analyst, who believes Activision's aggressive approach to mobile will continue to pay off, likes it and Zynga (ZNGA) as the best positioned stocks in the mobile gaming sector. Giaimo keeps Buy ratings on both stocks and increased his price target on Activision Blizzard shares to $68 from $65.