Shabbat, Chapter One, Mishnah Seven
This mishnah is related to the last couple of mishnayot in that again Bet Shammai and Bet Hillel debate and yet the subject is different. In this mishnah a Jew gives something to a non-Jew before Shabbat for the non-Jew to carry away on Shabbat.
Bet Shammai says: one must not sell [something] to a non-Jew, or help him to load [a donkey], or lift up [an article] upon him unless he can reach a near place [before Shabbat].
But Bet Hillel permits it.
Bet Shammai holds that one shouldnt create a situation where it will look like the non-Jew is doing forbidden work for the Jew on Shabbat. A non-Jew may not perform work for a Jew on Shabbat. Despite the prevalence of the shabbes goy, a non-Jew who does things for a Jew on Shabbat that the Jew cannot herself do, this is actually prohibited. Bet Shammai says that if a Jew sells something to a non-Jew on Friday or helps the non-Jew load up a donkey or the non-Jew himself, it will look as if the non-Jew is setting out to do the Jews work. Therefore, it is prohibited. In order for it to be permitted, he must arrive either at his own home (according to one opinion in the Talmud) or at least to his home city (according to another opinion).
Bet Hillel is not concerned with creating such an appearance, and hence this is permitted.