Ah the subtle art of persuasion. In the case of "The Passionate Shepherd to His Love", the word "art" can be taken both literally and figuratively. The speaker of the poem has cleverly and artfully designed what he thinks will be a winning argument, but he has used art, or artifice, to pull it off in the form of poetry. Does the speaker succeed? Does it matter? Tell us what you think, and remember… be convincing.
This dude is totally convincing. He basically promises the object of his affections a long, torturous camping trip, complete with really weird outfits and awkward serenades.
The speaker of this poem is persuasive, but untrustworthy. Which means the addressee should run for her life.