Did the Usatovo Dialect Spread Through the Black Sea?

Language can expand by virtue of people learning the language. And economic power, or trading power, can be a factor in that spread. So did these early eastern european people learn this usatovo dialect and then migrate westward into northern europe? The answer is probably some combination o both. Trade was probably a major factor at work here. As these people migrated and traded up the nista river, they probably established settlements along the way as these people spread.