Direct selling
This is face to face sales, when a sales person is directly approaching potential customers; the most common example is door to door sales. This method is generally used when the mark-up of the product is high, as it is a expensive process and has a lower conversion rate in comparison to other methods.
Some people feel it invades their privacy and direct selling has received a lot of bad press due to vulnerable people being targeted, through legitimate and non-legitimate direct sales people. Vulnerable people can appear as easy wins, and this occurs because direct sales people are on high commissions due to the low conversion rate of their prospects.
