Words, properly used, can be the most potent form of flirtation. Forget the subtle body language; the light touches, subtle smirks and understated winks. They're almost nothing compared to spoken dialect.
The human voice, by nature, is beautiful. Like music, it lilts on one's tongue and reaches a variance of pitch. To put that to work in cooperation with the mind of one in love.. It's amazing.
Both spoken and written, words achieve something in the seduction game. That something is the ensnaring of the recipient in a tangled web, binding that individual, and enticing them to reciprocate such language.
Like a moth to a flame, flirtatious words dazzle one into an addiction to the other person. Whether the addict is conscious of their enslavement, it is extremely effective. Isn't it?