If you approve the comments, you are giving them a link to their site. The way I look at this topic is, if the comment is good and adds to the discussion of your page, approve them as they will help you get more people conversating on your page.

If it is a "junk" comment, don't allow it.

I also have been having a lot of spam comments, and I do not approve them. I have been wondering how to encourage people to comment on my blog. I post a lot at forums in my niche and I get comments there, sometimes even about my blog. But I have only had a few people actually comment on the blog itself. Any suggestions for encouraging people to comment?

I dont approve spam comments. They're not beneficial to your blog and it clogs it with non-sense, hurting real commenters on their real conversation.

I only approve these if they have genuine content that could be interesting or useful. If they put thought into the comment, they deserve the backlink. Otherwise I delete the comment or just remove the backlink.

If it is purely rubbish, or horribly misspelled, then I delete it.

What about someone who writes, "I really enjoy your blog"

Is that spam? Should I approve it? Do I get any link credit or is it a one way link?

Nope. If the comment isn't directly related to the post, I suggest simply deleting it. You can always tell the ones that are spam from the ones that are genuine. You can also tell by the "name" they put in the box - especially if it is anchor text instead of a real name and if they include a website link.

I would allow some of those comments if they really help you out. But some of them are so generic they are not worth it really.

I think the selling sites do not require comment, if you have questions you can make an email link in contact us.

I only approve the comments that have a real name and not using my site as backlinks, you do not want Google thinking you look like a spammer so if at all possible delete the comments. I understand having comments on your website might make your site look popular but as I said earlier you do not want spam comments!

Comments like 'I really enjoyed your blog' or 'I like the template of your blog where can I get it' - these are spam - delete.

I will only approve comments that relate to the post so it is obvious that the reader has actually read the post. Occasionally I get comments that are borderline - they do kind of relate to the post but sound a little bit sus - then I would check the link of their site and if it is a good quality site then I might approve it. If I don't like the look of their site then I won't.

One thing you can do, is disable links in your theme. That way people can still actively engage without pending moderation. I would do that and add in honeypot + spamtrap + a logic captcha