I look at who has contacted us lately, who has visited the website, who has signed up for a trial, what ads are running where and who did they target etc. It isn't about where you advertise so much as what they are doing for you. Also, who has asked for support, who has sent us an email and who is likely to convert.
Marketing is about keeping existing clients happy, finding the channels where new clients will be and experimenting. I will experiment in various places, but honestly, I rarely will check the results other than weekly.
I have 20 years of development and marketing, and one thing has held consistently true. It takes time to see what works and what doesn't. I don't mean it takes months or years, but you can learn nothing in an hour or two (generally), as it will take a week or more of testing and experimentation to see any patterns.
Why we choose this, is simply because while we see the most traffic from Facebook, the least number of conversions come from those ads. Retargeting and Display Ads do the best, outside of direct emails and follow up from on site visitors.