Starting a signature campaign is good because you can make your business known to the community but our main concern is to have a great result for our campaign, and I believe that in order for a campaign to be successful, you need to hire a campaign manager that is well respected in the community.
Someone may also run his campaign himself but that would make it quite harder for him to get some good campaign users as people wont believe if they will get paid or not if someone unknown or new to the community opens and runs a campaign himself without any manager or escrow.
It's true, so when your business is still new, do not compromise it if you will just invest, besides the fee for hiring a good campaign manager is not that expensive I guess, yahooo is a good campaign manager and I think his rate is just cheap.
I agree with you with a good and well known campaign manager your advertisement will get more exposure and your business will improve and you will get good return for your advertisement. So it is better that you first check with whom you are going to join after that you can start your own campaign.