Is it legal to enter everyone who submits a survey (on a website) into a raffle?

The laws governing contests, sweepstakes, and raffles are extremely complicated, because each state has its own laws, and any promotion open to residents of all states (not to mention countries) has to take the resident's home state's laws into account. That's why you see "Void where prohibited," and "Not open to residents of ____ states," because in some states, these are illegal. "Sweepstakes" are random drawings from a pool of entries, with various rules and odds of winning. "Contests" are games that require the entrant to have a skill of some sort to enter, and they are judged by a panel of judges and by objective criteria. "Raffles" are usually random drawings, with no skill involved, but which the entrant has to pay to enter. As payment is required to enter, raffles often fall under state gambling regulations. This isn't a DIY project -- see your own lawyer for help.