Blog commenting works as a traffic and link building tool so long as you’re not using automated spam commenting software. Life everything which works these days, your blog commenting needs to be natural or in other words manual or perhaps better said, relevant. The only way to leave relevant comments is to read the post and create a unique comment based on that post.
Ideally your comment will add an insight not covered in the post itself, something which readers of the comments can value from and consequently will be impressed to the point of clicking back through to your site. You can read a lot more about what makes for good blog comments, but this is about how to find timely blog posts to comment on.
There are two ways to do this. First you can build a list of relevant blogs worth commenting on by doing a Google search for blogs plus your keywords of choice, then check to see what kind of traffic that site gets using Alexa, for example. Once you have a handful of blogs related to your niche/site then subscribe to their RSS feed so that you can be the first to hear about the latest new content on that site, assuming of course you check your RSS aggregator of choice on a regular basis.
The other way to do this is to make use of Google Alerts. This is a free service where you can search for and receive updates from blogs related to your niche by keyword.
You can choose the frequency of how often you receive updates whether that’s once a week, one a day, or as soon as Google Alerts clocks something new which is the recommended setting for what we’re trying to accomplish. You should choose “all” results over “only the best results” to get all of the results, not just the ones which Google thinks are the most relevant and best for your search. Finally, enter your email address of choice which you want the alerts to be sent to and you’ll be alerted every time a blog makes a new entry related to your keyword. You should set up multiple
For more information refer to this video on how to use Google Alerts to find relevant blog posts right away to leave the first blog comment: