They would just add to the other slow boards such as Portland, Denver, New Mexico, Kansas, etc. The newest regional board added was Alabama after a bunch of people cried for a board there. Now they got their board and as predicted, hardly anyone posts there (6 months to reach page 3) Fallon has almost single handedly held that board up.
Even though I am in Hawaii, I am not necessarily in favor of Hawaii having its own board because I know it would be a dead board. However I have been in favor of grouping slow regional boards together. For example:
Alabama, Mississippi, Louisiana;
Kansas and Missouri, and maybe a couple other midwest states;
Seattle and Portland, and maybe some other northwest states such as Idaho and Montana; Arizona, New Mexico,-- maybe Utah could be with them.
Hawaii could be grouped with Alaska and Guam and maybe Puerto Rico and the Virgin Islands.
This way you wouldn`t have a board covering one small dead area but you also wouldnt have to use the all encompassing "other cities" board.
For now you just have to use the "other cities" ad board. Obviously there are also non TER boards that serve those areas too, so as far as advertising you will have to branch out if you visit. I also have heard that SLC has a high LE presense as far as the hobby.