1. This is a valid point, but I'm not sure anyone on this thread are distinguishing between giving the Gospel and giving a personal witness.
2. WOTM is a method of evangelism. There is no such thing as a method of witnessing, really. Giving a witness is telling what you have seen and heard--how you got saved, how God worked in your life.
3. I don't see much point in doing Spirit filled and led evangelism without expecting God to work--in other words, soul winning. If the Holy Spirit is at work, people will get saved. More will get saved in some cultures than others. I worked for 33 years in a Gospel-resistant culture with less than 1% Christian and only 1/2% evangelical. Yet we saw some blessed fruit that remained: Mr. Wakamatsu, Miss Nakajima who went to another church later but taught SS and sang for them, Mr. Togo the drug addict, Mr. Habazaki the mentally slow man who became my partner in evangelism and in going to baseball games, Mr. Usuki the yakuza gangster, Mr. Ushiro the drug addict and many others.