As the chart above shows, three in four SMBs would prefer to work with a single marketing provider or individual, but the reality is about two in four work with 2-5 providers. That means for every four SMBs, one prefers working with a single provider but currently isn't. Based on census data, that's about 6.25 million SMBs in the US who may be open to transforming their current marketing strategy in order to work with a single partner.
While these oversimplified estimates don't take into account the do-it-yourself SMBs or those surviving off word-of-mouth, the takeaway appears to be the disconnect between what SMBs want and what they currently do. This contradiction between preference and the reality is representative of either the SMBs' less predictable nature or the fact that those seeking one provider aren't satisfied with what the market has to offer at this time.
None of this is to say that specialization has no place. In fact, the data goes on to say that one in four prefer working with multiple firms that each have expertise in a specific marketing area. However, those who prefer working with multiple vendors are likely on the larger side of the SMB spectrum, with larger marketing budgets.