Publishing in low quality conference vs posting in arXiv We got a small set of good outcomes from some work that we were doing in recent months. However, the outcomes are not so good to be published in good conferences (CS). 

So, we decided to post and keep it online via arXiv.

Recently, one of my friends rang me and asked to publish the work in not-so-reputed conference (preferably, IEEE).

I was wondering, is it a good idea to publish it in bad quality conference? Will it give a bad name to us? 

Could we get some inputs although we know that the work could still be published after arXiving?
It probably depends on the "bad quality conference".

There are some conferences that are not the "top" conferences, have relatively high acceptance rates, and don't necessarily get the most exciting new results - but still do legitimate peer review, have respected experts in the field on their committee, and generally attract good attendees from good programs, albeit not with their very best work. These conferences are very much worth submitting work to and attending. You will get to network with people who are generally doing high quality work, get useful feedback on your own work, and hear some interesting talks.

(Many of the workshops that are co-located with the "top" conferences also fall into this category. These are especially useful, because you can also attend the main conference, and some people from the main conference will attend the workshop. They have many of the benefits of publishing in the "top" conference, but have much higher acceptance rates and are often a good venue for less mature or less exciting results.) 

Then there are conferences that don't do high quality peer review, whose organizers and TPC are not particularly well known or respected, that have a very broad scope (so the attendees are barely interesting in one another's talks), and whose proceedings are riddled with plagiarism and work with serious methodological flaws. I would strongly recommend against submitting to these. You will not gain any of the benefits mentioned above. You will waste money traveling to and attending the conference. Publishing in such a conference will preclude you from ever publishing this work in a more reputable venue. It can also signal a lack of judgment with respect to where to publish - while many people will excuse this as just a lack of experience, it is still not the impression you want to leave on people reading your CV.