For the last 24 years, I have always use the 5 lines system. You must always try to have 5 non-break off lines especially if you are full-time in the business. However, you should not stop sponsoring after you have 5 lines. Continue to prospect and sponsor but what I do is I will put these new people under the 5 lines. (Be careful that some will disagree with me on this, Please ask your upline.)
When you give them these new distributors, remember you must ask for something. For example: the distributor must bring 2 new prospects for you to do an opp. Always put the extra new distributors under your best lines, not to the lazy or not committed distributors.
The most important thing you must never forget is when you put the extra new distributor/distributors under your non break-off lines, you must look after them like they are your 1st generation or personally sponsored line until they like and know how to work well with their upline.
Whenever you break off a leadership line, you must start another new line to maintain the 5 non-leadership lines. I sponsor very fast and usually I have so many new distributors that I just put under my good leaders to make them solid and also as a reward. Again, I look after them like they are my 1st generation line until they know how to work together.
Lastly, the thing you must never do is to add a certain buy up volume to this system. I have people who learn from me this 5 lines system and then they added that everyone must buy up say USD 1,000 or USD 2,000 and claim I taught them this. I taught them the first part. I never teach them the second part.