Like any small business transaction, the buyer needs to have the skills in order to operate the business successfully. In the case of marketing agencies, this means that other marketing agencies are the most likely acquirers.
In addition to their own marketing efforts to obtain clients, marketing agencies can look to acquire another agency to expand their client book. This is most commonly seen with a larger business acquiring a number of smaller businesses. Although, there are a number of incidences of the minnow eating the whale as well.
Another buyer of marketing agencies could be a career changer from either the IT or tech industries.
Many professionals desire the lifestyle and freedom that small business ownership provides and are often times able to get very favorable financing terms from the SBA to acquire a US based marketing agency. This will likely be the most desirable scenario to sell the business, as SBA loans make for cash closes. However, the business must be based in the US with clean tax returns for the past two years and the buyer must be able to prove that they are a capable business manager.