Not hating on the post, just have a differing opinion on multiples.
As a fact of a matter is there are different types of business models in any industry. As far as domaining goes, selling on multiples is a way to go if you cannot find an end user and someone else can (or in your case, change a keyword and make more money on it). Though, would you go through each domain and purchase them for $60 a piece if they had $1/mo revenue. They make registration fee per year, add to your profit margin and you could quite possibly end up selling it to an end user for much more than $60 in the end. However, how long will that take while you only added $4/year to your portfolio with the time spent of buying, transferring, renewing, keyword targeting, etc. Is that extra $4/year worth it with the time spent modifying the domain? In my opinion, no.
If a domain made $100/mo and it had sustained statistics from a reputable member, it would depend on the quality of the name as well as the source region of traffic. Could I build a website over that parked name and make more? If I could, I would offer 2-4 years income.
When you get into domains making $300-$500/mo parking, it's a whole new ballgame as those domains are typically very generic or have type-in traffic (and should be developed rather than sold), though some of these domains are trends and the earnings may die out within a year so it's important to look at every aspect of the name before making a purchase to have a positive ROI. At that point, I would look at the name and determine whether it's worth a 5 year multiple or more (which tends to be the case for these ones as they're solid earners and have a long history of earnings, though as mentioned, some are trends or "typos" from other websites that you may not want to invest in).
Solid points on 5 year multiples. Though in my opinion, the name itself has to be broken down and categorized if it's worth the purchase or not, be it $60 for $1/mo or $12000 for $100/mo.
