Domain name length and keywords relevance in it. Blog advice

Hi!
Please, advice me about the following questions: I am going to promote my site where I sell software products in search engines (esp. google). To achieve this, I am going to establish a few blogs on it.
1. What name should I better take for the blogs: _blogname_._mywebsite_.com or _mywebsite_.com/_blogname_ ?
2. I would like to include keywords in the _blogname_ (I've heard it is very important). Is there a limitation for the domain length for SEO? Probably, gogle detect to long names as spam?

Thank you in advance,
Best Regards,
Vitaliy

 

The shorter the URL the better, you should use "sub domain" thats "blog.website.com"

 

But how to get the balance for "shorter domain" and "include keywords in domain name"?

 

Actually, I would like to make a few blogs for different keyword groups... Is this a right decision?

 

Sub-domains are generally thought of by Google at the time of this writing as separate sites so you'll need to work harder to rank.

 

For official blog site, I think it's better to keep the domain as blog.domainname.com. This is easier for people to remember and everyone will know it's the website's blog. When you are writing blog, do remember to add tags for each post. This will function just as the keywords in my opinion.

Generally, aside from official blog, I would create several other blogs which contains keywords in domain name.

 

Thank you very much for your answers!

Great Idea, thank you! When considering these other blogs, each blog will contain a few keywords. Is it right to give then names like _45 characters for keywords_.website.com? Or it is stupid?