Length doesn’t have much to do with a domain length selection. It is better to have a short and easy name so that chances of typos and misspelling are less. The number and hyphens are better to be avoided. The domain name should give a reflection of the content of a site, and is good enough to stand out in a lot.
You definitely don't want it to be too long. You want it to be something that the people could remember and relate to so that they can feel comfortable in going to that site. You want it to have something to do with what the site is about, but K.I.S.S. which stands for Keep It Simple for the Stupid.
I agree that length should not be a main concern, but you don't want a long name either. You want something simple, easy to remember, and easy to spell. The longer the domain name is the more likely it would be misspelled and then your potential user ends up on a different site then yours.
There are popular websites with long names but they worked because that name is memorable and catchy but if you look at the most successful websites, most of them uses one word only. People tend to remember one word websites.
Look at the length of these websites names:
Majority of successful websites have short names. Long names would work if you can think off a catchy name. These are some successful long named websites:
At the end of the day, its the quality of the content or the functionality of the website that makes people visit it over and over again. I hope that I gave you some ideas to make your decision.
I think domain names can be of any size, as long as you can brand them and they are easy to remember. For instance, WHDF.com is very easy to remember, except it has 4 different letters which some may find difficult to keep track of. Yet, if you had WebHostingDiscussionForum.com, I would find that much easy to remember. It has 4 words, and while it may be a pain to type in every time, it's very brandable and can be put to good use.
Google only shows 65 characters from your title/link. Therefore, anything longer than that will be left out by Google. Domain names must be catchy and easy to remember. Even longer domain names can be catchy and easy to remember, but it is frustrating to type the long name.
K.I.S.S, Keep it simple stupid. That is the motto for everything when it comes to business. The simpler you keep it the easier it is for you and your customers/clients. This is the best and easiest way to both obtain and maintain those customers/clients. Otherwise to determine from your site/business.
I think it needs some skill to find out the sweet spot when it comes to domain names. The name must be as short as possible, at the same time, it should reflect the content it is dealing with unless you are confident to make a brand on your own. If the name is too long it will be difficult for the user to remember the entire name, as a result, more typos and they may end up in another website. When it comes to choosing words related to the content or product you deal with use some catchy words after doing some keyword research. I think, the domain name should not exceed 10 characters.
You don't want to have a name that is too long or too hard for people to remember. You want the name to be short and easy so people will not forget and it will be quicker for them to type in the browser. Another thing you don't want to do is add those special characters to a domain like a - symbol as it can confuse people too.