After becoming the first team in major professional sports to return to it's original city. San Diego returned to Los Angeles where it's origins lie. The St Louis Rams, last year, returned to Los Angeles. Now the Raiders are moving for the third time. The team will head for Las Vegas becoming the first major sports team to leave the same city twice.
For me it looks like teams in the 1990s moved to cities where they could connect with blue collar fans. After about 20 years of no NFL moves, it seems now that teams are following the money.