The exploding offers I love the most -- are the ones that come after a ridiculously long process, itself saddled with weeks of radio silence and surprise extra rounds. Topped with handy-wavy descriptions of benefits, and essentially no room for you to ask questions about actual working conditions.
Asking for a new or increased substantial sign-up bonus should allow a genuinely hasty employer to put their money where their mouth is and a merely aggressive employer to find time.
Because why wouldn't you just love working there?