What a silly question. Just because you send a sample means that the person will buy?
There are no guarantees don't send any samples that you can't afford to loose.
Keep in mind that starting a b usiness takes time, so the person might need to show the sample to a few people, possibly even borrow money, make a plan etc, sourcing is only the very start.
We are in the industry of building materials and most of our clients won't buy within two weeks after they receive our samples. Some has to do the test, some has to show samples to their partners, some has to show the samples to their customers, and some is waiting samples from other suppliers for comparison. Be patient and good luck!