I am looking to buy a 2 keyword domain, but all the dash & non-dash variants have been taken. What is the value of a domain with 2 dashes? Example: www.word1--word2.com I realize that the negative would be that people forget to type in 2 dashes if they return. But what about for search engine rankings? I mean it tends to be easier to rank a website for a search phrase if the search phrase is right in the domain itself, even if it has 1 dash. What about 2?
There's a reason why double dash domains are widely available - they look and feel spammy. If you are dead set on having 2 keywords in the domain, why not get something like KW1KW2 "Tips" or "Guide" or "services" - that way you can perhaps indicate to a potential reader what your site will offer.
You won't get penalized in anyway by search engines, but yeah like Rank said, they give a spammy impression to users. Also very annoying to type for Direct Traffic.
Double dash just sounds painful, do whatever you have to do to get a single dash or better yet - no dash at all