i dont see whats the purpose of offering so many domains allowed. the customer only needs 1 domain. why are there websites that offer like 10 domains allowed and etc. hostgator allows unlimited domains allowed. whats up with that? can someone explain why the customer would need more than 1 domain?

If you have multiple domain names and you want to host a website off each of them, then a hosting plan allowing multiple domains would allow you to host each domain of that single hosting plan instead of having to purchase a new hosting plan for each domain.
Some do it through Add-On Domains, which creates a sub-directory within /public_html (such as /public_html/newdomain2.com). The data is then uploaded to that directory and when newdomain2.com is entered into the browser, the data is shown.
Others do it via WHM (Web Host Manager) which allows you to create a new account and each account created will have its own CPanel login (whereas Add-On domains do not allow separate CPanel logins).

RockStarComm is very right, hosting providers that allows multiply domain names which many do now as standard allows customers to host as many websites as they please and point each domain name to a different folder within the home directory of there account.

the customer only needs 1 domain. That's an assumption, just as it is saying a family only needs room for one car in the garage. It may be true for many, or even for most, but there will always be exceptions. :)

Multiple domains allow to host more then one site on same host package. I have like over 10 domains on my shard host plan.
You can also setup so that 2 domains go to same site.

I have around 40 domains, some for development, some to redirect to other sites; if a host limited to 1 I'd run a mile. Why on earth would you limit to 1?!

i dont see whats the purpose of offering so many domains allowed. the customer only needs 1 domain. why are there websites that offer like 10 domains allowed and etc. hostgator allows unlimited domains allowed. whats up with that? can someone explain why the customer would need more than 1 domain?
If you bought hosting from a company that limited the amount of domains you could host to one, would you seriously buy a second package from that company? I'm pretty sure you'd rather save the money and buy hosting that allowed more domains.

If you bought hosting from a company that limited the amount of domains you could host to one, would you seriously buy a second package from that company? I'm pretty sure you'd rather save the money and buy hosting that allowed more domains.We only allow one domain per account and have countless customers who have purchased our multi-site addon plans. Limiting the amount of domains customers can add to their account not only increases overall quality and performance of the server, but also allows the host to maintain a controlled (non-overloaded or oversold) environment. You also won't have customers randomly creating new websites (which also increases resource usage), just so they can use all of their domains.

i dont see whats the purpose of offering so many domains allowed. the customer only needs 1 domain. why are there websites that offer like 10 domains allowed and etc. hostgator allows unlimited domains allowed. whats up with that? can someone explain why the customer would need more than 1 domain?
Because it is cheaper and more convenient for people to host multiple domains within one hosting account than to order several packages and host each website separately! Hostgator hosting is a good solution for webmasters with multiple domains!

Don't forget the marketing aspect of this type of offering. From a consumer standpoint, ten domains allowed for the same price as one domain allowed is much more attractive.