The first thing that determines whether the amount of content which you are producing, is enough or rational for your long term success with article marketing, is to take a look at how much content you are currently producing on a frequent basis. If your major goal with article writing and marketing is to be making upwards of $1000 a month, respectively you may need to either step up your game in terms of hitting your target audience spot or be publishing several high quality posts every day. However, if your main objective with article writing is to simply entertain an audience, and/or make some money along the way, a significantly less amount of articles are required.
Another thing to take into consideration is what kind of audience you are trying to write for. Some audiences demand that you post content daily to suit their needs, whilst others only require posts once a week or so. To determine which category your audience fits in, ask yourself what your audience reads your content for. Is it to gain knowledge? Find humour? Be updated with news reports and details? Or just to read your own opinions of aspects of the world which are controversial and debateable. Once you fully understand what your reader is going to you for, as well as just how much they expect you to be writing, you can map out a suitable plan to meet these needs.
A final demining factor which will ultimately decide if you need to be writing more content for your goals to be achieved is whether you are trying to compete with another major with your topic. If you are writing on a similar topic that another writer is doing, but he/she is writing a lot more than you, that is a clear cut sign that you need to start publishing more content. With that being said, if your content offers a lot more quality that your competitor, then it is most likely more beneficial for you to post as many articles as you can, whilst maintaining your quality.
Now in terms of evaluating how your increased productivity with writing articles has affected your success, the most effective way to go about this is to monitor your traffic increases, revenue increases and overall involvement from other writers such as yourself. If you are noticing increases in all of these fields after around 2-3 months of having tested an increase productivity rate, then you definitely know that what you're doing now is going to be beneficial to you later down the line. However if you've noticed a decline in the amount of traffic/earnings that you are getting on your content, then it's possible that you are either writing too much or your quality has diminished.
To find the best results for you at this stage, the best thing you can do is to play around with how much you publish, and how much time and effort you put into each post. When you finally see a trend of an increased traffic and earnings within your results, you can be sure that you are on the right track for article wriitng and marketing success!