Buyers are more likely to believe a seller's optimistic view of the business' future when seller financing is offered. Some buyers can't or won't look at businesses for sale unless seller financing is a possibility. The more buyer prospects that look at a business, the better the chance a seller has to get an acceptable offer. A seller can also get a better price for a business that has financing in place. As in nearly all buying situations, buyers are often focused on achieving a purchase on terms that allow them to buy with as little 'cash in' as possible, even if the long-run costs are higher.
Seller financing can also lead to a speedier sale.
If the seller plays bank, then the deal gets done more quickly. Banks also move much slower than sellers, even when they do approve a loan. A seller is more much likely to grant a loan request, approve a transaction, and close it as fast as the attorney can get the agreements prepared. Banks take anywhere from thirty to 120 days to approve and close a loan. There is also the possibility that the bankers will give the buyer negative feedback about the business, so that the buyer backs out.