Early Access is Not Enough
One very common thing I see over and over again is a call to action with something like “Sign up for Early Access”.
This use to be enough to get people to sign up. But now, it is so prevalent that I find it to be a big turn off.
Think about it this way, this is your first transaction with the customer. Do you really expect them to pay you for something and get nothing in return?
The most successful pages I see are the ones who find away to provide something small (often educational) to their new potential customers in exchange for their emails. It also has a side effect and providing more incentive to use a good/valid email address.