This is the question almost everyone asks first, and it is also the question most content in this space answers badly, either wildly overselling it or staying so vague the answer is useless. Here is a straight version.
Why there is no single number
Every matched betting opportunity is tied to an actual sportsbook promotion, and those promotions are finite. A welcome offer is worth what it is worth once, not repeatedly. So the honest way to think about the total is not a rate you earn continuously, it is closer to a pool of one-time and occasional opportunities that gets restocked slowly as sportsbooks release new promotions in your state.