Just a few sentences will probably work well. We'll get into details later on.
Please don't say "anyone who sees my site!" Think about those are most likely to want to buy/use your products or services.
Or hate, too! If there are some sites that you think do a good job, or look like what you want, that will help.
For example, you might want people to be able to download a helpful article, and you want to add them to an email list.