I am generally in the “Raise your Price” group but in this case, I am not sure if $29/Month or higher is a good starting point. You are competing with services such as Disqus and Facebook Comments primarily. For any customers who are already on Disqus/fb comments, it will be a real hard sell to switch. If the argument against Disqus is ads, then their premium plan is only $10/Month (no ads).
I would advise introducing a lower tier, possibly single digits.
Also, if I am a blog owner, why should I pay based on how many pageviews I am getting ? I would rather pay based on the activity and comments if at all. So if you do want to charge based on activity, why not restrict the number of comments etc. in a lower tier on a specific post ? Something like:
- Up to 10 comments per post in lower tier
- Unlimited comments in higher tier (or choose a higher limit if not unlimited)
This way, if the blog owner is not getting a lot of activity, they are not forced to pay the higher tier. If they do generate enough activity, they will then be more inclined to upgrade. My 2 cents.