Network Marketing Genealogy Lists show you the whole structure of an MLM business right from the earnings at the different levels of the organization,

to how the company was structured and the different levels that were in place.
In a sense this is like the heartbeat of the business, because network marketing genealogy is ultimately a bit like the DNA of the business. It is a microcosm of how that business operates in the real world.
Sometimes these lists are auctioned or sold off, particularly when MLM companies go out of business, because essentially they are still assets of the business. They show lists of distributors for example, which is potentially a very lucrative source of new lead opportunities.
However, it is worth bearing in mind that simply because a distributor was interested in working for one MLM company, that they will not automatically be interested in working for yours!
So, you may find that if you buy one of these lists and then contact the distributors on it that you won't automatically be welcomed by them with open arms!
Sometimes these lists find their way to general distribution online, and so it may also be that these people are being bombarded with calls with all manner of different companies. So that after a while another call from a network marketing company may be the very last thing that they want!
If you do want to explore the possibility of buying such a list then you need to make sure of exactly how fresh it is, and also how exclusive it is. If it is being offered to a variety of different parties then it may cost less to buy, but the effectiveness of the data that it contains is going to be dramatically less useful. Exclusive data arrangements for Network Marketing Genealogy Lists may cost you more money, but the fact is that they may well be worth it.
If you are the first person to contact a distributor from another network marketing company that has sold their list, then you are likely to get a much warmer reception then the fifteenth! So, the conversion rates on the data are also something that you need to bear in mind before you commit to buying any data.
If data is sold to multiple companies then it is also fairly likely that some of those companies will also go ahead and resell the data. This has the effect of massively multiplying the amount of people that have access to that data, and so it is not uncommon for it to very quickly become over-used.
None of which is to say that Network Marketing Genealogy Lists cannot potentially be a goldmine of new lead sources! But the fact is that you need to make sure that the data you buy is fresh, exclusive and not offered anywhere else. If you make sure of those things that it can potentially be a really good investment.