Snap bid or cob

BUMP

Snap bids are given out after bid matching but typically before bid day starts, meant to bring a chapter that didn't reach quota up to quota. For example, after bid matching, if quota was 100 and chapter XYZ has only matched 90, they are eligible to give 10 snap bids. Women who dropped out, didn't match through regular bid matching or quota additions can receive these bids.
COB are bids given out to bring a chapter to total, which is the total number of women in a chapter plus their new pledge class. These bids are given out after recruitment ends, and can be given throughout the year until a chapter reaches total. So if total is 350, every chapter below that, regardless of whether or not they made quota, can give out bids through COB until they reach total.
It isn't that one is better or worse, but hard to "count" on either. Snap bids are usually less common, and with a snap bid you go right to bid day/new member activities and really no one really knows except whomever is in charge of membership at any given house. The house would contact you directly for a snap bid.
Some chapters will have COB/informal recruitment activities later in the year, so potentially you could have more options.
I hope that helps?