Comment forms.

allow visitor's website?

[Karma]

I've seen many sites recently (blogs in particular) that allow you to enter your site URL when leaving a comment.

These URLs are not always shown and I'm just wondering whether there is any negative/positive effect or if this is just a feature of wordpress type blogs that webmasters fail to switch off during the initial install.

I created my own (basic) comment system for my site so I'm wondering if it'd be worth implementing. I suppose one benefit would be that allowing visitors to leave their URL may encourage message(aka content).

[Quadrille]

And one disadvantage may be encouraging either spam - or, possibly worse, 'bad' links.

Nofollow links will still encourage 'honest' punters - they'll get a few referrals if they post interesting and useful stuff, but they'll not get page rank, so no encouragement for blackheart blogspammers.

Of course you'll still get some, as many are too stupid to realize that nofollow removes their 'advantage', and few pharma sites will get many referrals (unless yours is a pharma blog!).

But you can build in safeguards; captcha type thingies, for a start, plus if you label your form fields with non-standard terms, you'll get few robot posters.

[martinibuster]

• Comments enables people to create free content for you.
  
• Comments encourages community and site-stickiness
  
• Comments allows you to discover interesting sites in your community/niche as well as become a part of that community

[graeme_p]

Wordpress, by default, shows but nofollows all links in comments. There are various plugins to modify this behaviour.

Personally I think that you should allow links, provided you can keep spam comments under control: if people have contributed to your site, give a little link love back.