A: For informational purposes, NOT legal advice:
In some service businesses, where there is not hard property asset value but the company is making money, an agreement called "earnout" allows the seller to continue working as part of the compensation.
For example, a consulting company may have ongoing business that is dependent on the seller being involved, due to familiarity and personal loyalty.
These agreements differ from seller financing in that the seller's employment is subject to continued business volume, therefore the buyer has some assurance that the seller (and their friends, co-workers, relatives,etc.) do NOT try to divert the existing customer revenue stream to a different business with similar services.
Yes, some sellers cleverly attempt to sell their business and then set up a competitor in their kids, spouse or relative name to recapture the revenue and tiptoe over the non-compete seller clause
In these situations the buyer may offer a Earnout to protect their interest and insure the revenue keeps coming in while the new owners learn the detalls and customer base.
Other situations where "Earnout" may be preferable include business sales where the subject business is a subcontractor or heavily dependent on one or a small few number of clients, which makes the business revenue stream highly subject to rapid change.
Buyers should be careful not to pay for a company AND then also do a "earnout" since that would be paying twice.