Do I really need to build a list?
If you are going to be marketing and selling on the internet then the answer to this question is a definite Yes.

When should I start building my list?
As soon as you have a distinct plan of what you are going to be selling or marketing

So why do I need to build a list?
Having determined we need to build a list, let's take a look at why this is necessary.

Do you intend to sell product or use your website to make money in some way? Of course you do. You wouldn't be here if you didn't want to make money and get paid for the time you have spent building your website.

While you may be using your website to educate others in your passion, or just generally to help those less fortunate than yourself, you still need to earn a living.

Any and all internet marketers will impress on you the importance of having your own list. A list is reckoned to be worth $1 a month for each list member if you use it properly.

Well that seems to me to be a very good reason for building your own list. Imagine having a list of 1000 members. If you use it correctly it would be worth $1000 each month.