Translators often classify clients as agency clients and direct clients. Regarding the supply side of the translation business, Neil Langdon Inglis many years ago posited that there was a de facto caste system among translators. Another approach is to discuss the translation supply side in terms of tiers, employing terminology that is commonly used in fields such as the auto industry, which might be useful in looking at the differences between translation and other businesses.
Tier One. In the translation supply chain, tier one (T1) is populated by translation providers (including agencies and some individuals) selling translations to translation consumers (as opposed to other translation sellers).
Tier Two. Translation providers that sell translations to T1 translation providers are tier-two (T2) providers. Most T2 providers, but certainly not all, are individual translators.
There can be more than two tiers. A translation provider selling translations to a T2 translation provider as a sub-subcontractor would be a tier-three (T3) translation provider.
For much of the translation sold by T1 providers, the value added by a T1 provider is often purchased from yet another T2 provider, in the form of rescue work to repair badly done translations from the first T2 provider.
In terms of who is selling to whom, the translation business tier structure is similar to the auto industry. Beyond that, however, there are some radical differences. The most serious difference is that, in the auto industry, the end-user (OEMs, the auto makers) most often know the identity of the T2 parts supplier that their T1 supplier is purchasing parts from. In the translation business, because most of the translation sold is sold by T1 translation providers having little value to add, the T1 providers perhaps rightfully fear losing their business to T2 translation providers if they disclosed the identity of their T2 suppliers. The result is that the identity of a T2 provider is rarely revealed by the T1 translation provider to the end-user (translation consumer), and the identity of the end-user is, when possible, kept hidden from the T2 provider.
All evidence I have seen indicates that only a tiny portion of the people working as and calling themselves translators will ever become T1 providers. This view is supported by long years of experience and interaction with translators. The reasons are various, some attributable to decisions made by the translators themselves, including the choice of the place to live and the choice of source languages from which to translate. Others reasons relate to the ability of individual T2 providers to grow to the point of taking on the role of a T1 provider. For my language direction (Japanese-to-English) I would estimate the proportion of translation practitioners who reach the T1 ranks to be significantly less than 5%.
Given the above, I sometimes wonder about the value of even attempting to suggest to translators strategies for taking on the T1 translation provider role. Very few will ever achieve that, and the ones who will get there will most likely get there without suggestions from me.