Advantages

An EIP has the following advantages:

Flexibility
EIPs can be flexibly bound to or unbound from ECSs, BMSs, NAT gateways, load balancers, or virtual IP addresses. The bandwidth can be scaled according to service changes.
Cost-effective
EIPs are available on a pay-per-use (billed by bandwidth or traffic) or yearly/monthly (billed by bandwidth) basis. You can use shared bandwidth to enjoy lower bandwidth costs. Generally, if you have frequent data transfer needs, a yearly/monthly subscription is a more cost-effective option.
Ease of use
EIP binding, unbinding, and bandwidth adjustments take effect immediately.