What Are The Primary Uses of a Proxy?

I just wanted to know before I even consider buying one. I've thought about it a few times, the problem is if you are buying one because you got IP banned from a site you need to use for marketing then what is the point? Wouldn't you just get the proxy banned and then have to buy another one again?

Just a little confused...

I can be used for multi purposes. depends on you how you you wish to work with it.

If you get your IP banned because it's 'overused' then multiple proxies can solve your issue as you have multiple identities.
However, if other reasons get you banned you might want to change the way you work.

Okay, thank you both.