Structurally different products with interchangeable marketing. Which one is better for you depends on what you were going to bet on anyway.
Sportsbook bonuses and casino bonuses look identical on the landing page, because they are designed to. The mechanics are different enough that picking the wrong one for your play style can cut the expected value of your first deposit in half. The following is a structural comparison, not a ranking.
The common sportsbook welcome offer is a free bet or a matched first bet. A free bet of $50 means: place a $50 wager; if it loses, you lose nothing; if it wins at +100, you receive $50 in winnings and the stake is not returned. A matched first bet means: your actual $50 is at risk, and if it loses, you get $50 in site credit to try again.
Rollover on sportsbook offers is typically 1x to 5x on the bonus amount at a minimum odds floor (usually -200, equivalent to 1.50 decimal). Push bets and voids do not count toward rollover and do not void the bonus. Expiry is usually 7 to 30 days.
Expected value is high because the rollover is shallow and sports outcomes are closer to 50/50 than casino outcomes are. A $50 free bet at -110 returns about $22 in expected value. That is an unusually good bonus in any vertical.
The common casino welcome is a matched deposit at 30x to 50x rollover. You deposit $200; the casino credits $200 bonus funds; you must wager the bonus (sometimes plus the deposit) 30 to 50 times its value before any of the bonus or its winnings can be withdrawn. Slots contribute 100 percent of each wager toward rollover; table games contribute 10 percent or less; live dealer is often excluded entirely. Max bet during wagering is usually capped at $5 per spin or per hand, and exceeding it voids the bonus without warning.
Cashback is a variant: the casino returns a percentage of your net losses over a week or a month as bonus funds or free spins. Rollover on cashback is typically lower (5x to 10x) but the underlying product is a loss-share, not a match.
Free spins are a hybrid. The spins themselves have no cost, but winnings are usually subject to their own 30x to 40x rollover before withdrawal.
Sports offers at 1x rollover on 1.50 minimum odds convert at roughly 66 percent of face value in expected terms. A well-structured free bet, because the stake is not returned, converts at closer to 40 to 50 percent of face value, but the rollover is also 1x, so the blended EV is similar.
Casino matched deposits at 30x on 3 percent edge slots convert at about 40 percent of face value in expected terms. At 40x, about 30 percent. At 50x, under 20 percent.
For the same face value, a sports offer is usually worth more. The catch is that sports offers have lower caps ($25 to $100 typical) while casino offers scale to $500, $2,000, or higher, so the absolute dollar value can flip.
Pick the bonus whose vertical you were going to wager in anyway. Do not pick a sportsbook bonus if you do not follow a sport; you will end up betting on markets you do not understand to clear a rollover and giving back the theoretical EV to variance. Do not pick a casino bonus if you dislike slots; the contribution weighting will punish you.
A second-order rule: if you are between the two and deposit size is small (under $200), the sports free bet almost always has higher expected value per dollar of bonus. If deposit size is large ($500 plus) and you will play through significant volume anyway, the casino match can convert more absolute dollars despite the lower per-dollar EV.
Rarely on the same deposit. At Stake, sportsbook and casino welcomes are separate tracks and you commit to one at first deposit. Roobet is casino-first with an optional sportsbook side quest after registration. Razed is similar. Bet105 is sportsbook-first with a small casino upsell that is not strong enough to switch for. Reload offers (post-welcome) often cross verticals more freely, because the operator has already qualified you.
Three numbers to find before clicking the bonus opt-in: the rollover multiplier, the minimum odds or game contribution, and the expiry date. If any of the three is missing from the on-site promotion page, assume the worst reasonable value for each and re-check the math. Most bonus complaints in operator support queues trace back to a max-bet rule that was not prominent on the landing page, which is an intentional design choice and worth routing around.