When you create multiple Paths, they are automatically assigned a default weight of 100. This is to ensure that your traffic is distributed at an even ratio for a new campaign.
Note: You can edit your Path’s weight at any time to redistribute traffic at an optimal ratio.
You usually do this once the performance of a Path has been accurately measured following the campaign's “testing” period.
For example, if one lander is doing better (higher CTR %) than another within the same campaign, you can increase the path weight of the best performing lander to distribute traffic at a higher ratio to the better performing landing page.
Tip: A weight value can use any numerical value. If there are two landers, each with a weight of 1, traffic will be distributed at a 50:50 ratio.