user4108: On this post, I attracted the attention of two particular users in the comments using "@Username" because I think these guys might have an interesting answer to give.
I am not forcing them to answer but only attracting their attention. Is it good to do this? Now that I start to know the field of interest and knowledge of different users, should I almost always attract the attention of the people I think can answer my questions and the questions of others?

user6: Well, the first thing is that your @notifications didn't do anything. They only work for users that are either the owner of the parent post, have commented on the parent post or have edited or closed the parent post. You can't use them to attract users that haven't participated on that question.
Generally you can assume that users interested in certain kinds of questions are monitoring either the site or this specific tag (with our volume looking at the entire site is still easily feasible), so there is probably no need to ping them. If you know the user well and they don't mind you could ping them in chat if they use it. I wouldn't do this for a user I don't really know, though.

4108: <p>On <a href="https://biology.stackexchange.com/questions/16621/list-of-np-hard-problems-in-biology-bioinformatics">this post</a>, I attracted the attention of two particular users in the comments using "@Username" because I think these guys might have an interesting answer to give.</p>

<p>I am not forcing them to answer but only attracting their attention. Is it good to do this? Now that I start to know the field of interest and knowledge of different users, should I almost always attract the attention of the people I think can answer my questions and the questions of others?</p>
 6: <p>Well, the first thing is that your @notifications didn't do anything. They only work for users that are either the owner of the parent post, have commented on the parent post or have edited or closed the parent post. You can't use them to attract users that haven't participated on that question.</p>

<p>Generally you can assume that users interested in certain kinds of questions are monitoring either the site or this specific tag (with our volume looking at the entire site is still easily feasible), so there is probably no need to ping them. If you know the user well and they don't mind you could ping them in chat if they use it. I wouldn't do this for a user I don't really know, though.</p>
