Our guarantee is fairly simple. At the start of a project, we invoice half of the professional fee. The other half of our fee is invoiced at the end of the engagement. That second half is paid according to the client's satisfaction level. If dissatisfied–don’t pay anything. If satisfied—pay the full amount. If incredibly satisfied—pay up to 150% of the final invoice amount.
As a firm, we believe it is a good practice to have our incentives aligned with those of our clients.