With so many offers across the board for opening new accounts, there is more than enough of an argument for opening multiple profiles with multiple sportsbooks. There are several advantages to this strategy with a few detractions mainly being that it is a lot to keep track of.
Be aware that opening multiple accounts is not a perfectly easy strategy, inevitably you will have to create some sort of spreadsheet to keep track of your various accounts, offer expiration dates, and times to bet that if you follow through the rewards can be worth the effort.