It might, but keep in mind that the signals from the client still have to be able to get back to the WAP -- if the client can 'hear' the WAP from, say, 200m away, but the WAP can only 'hear' the client when it's <= 50m away, your effective range is only 50m.
Boosting the signal too much might be an FCC broadcasting violation -- there are limits on how powerful a radio transmitter you are allowed to run without a license (although nobody is likely to complain unless it's powerful enough to screw with other nearby equipment). You are unlikely to start microwaving anybody with commercially available amplifiers and antennas. 😛