$220\mathrm{.}3$ points

Dropbox, Uber and PayPal used similar strategies when trying to jumpstart network effects that were vital in creating their dominance. What did each do$?$

Leveraged viral customer promotions by giving incentives to consumers who helped recruit friends to the service.

Preannounced their products, discouraging rivals from entering with competing offerings

Paid subscribers for following them, enforcing the "fake it until you make it$"$ rule.

Created services that were backward$-$compatible with rivals, reducing switching costs for anyone interested in leaving incumbents for their services