I have worked in and out of consulting and agencies for many years and I have a simple rule for hiring them when anyone asks:
1. Are you going to be one of their three biggest clients? If not, find a smaller agency.
2. If you can't find an agency small enough to be one of their three biggest clients, you want a contractor, not an agency. Put them on retainer for more than 50% of their time.
Firms will bend over backwards for their largest clients because they do a poor job of tracking that it is costing them money when they need to fix a mistake. They just see one of their biggest clients is unhappy and they will lose them.
1. Are you going to be one of their three biggest clients? If not, find a smaller agency.
2. If you can't find an agency small enough to be one of their three biggest clients, you want a contractor, not an agency. Put them on retainer for more than 50% of their time.
Firms will bend over backwards for their largest clients because they do a poor job of tracking that it is costing them money when they need to fix a mistake. They just see one of their biggest clients is unhappy and they will lose them.