Last week American Express offered a 75,000 bonus for the Business Gold Card with only a $4k spend –> See my post here. That offer lasted less than 1 day.
Now they are offering another 75,000 bonus offer which expires tomorrow – 5/17/13.
This offer requires $10k in purchases in the 1st 4 months which is not as good as the one last week. Its unlikely they will offer this offer again with only a $4k spend but who knows. If spending $10k in 4 months is easy for you, then sign up while you can. Otherwise, look out for another similar offer in the future.