What sort of multiples should be a fair guideline when putting a value on a site that is for sale which purely aimed at generating adsense revenue?
I think it should be at least one year of adsense income. And more if there is potential for improvement.
So we have one year and 6 months, quite a big difference in valuation on those multiples, any other view points?
It depends on a number of factors including how long the site has been established, how stable the income has been in the past, how popular/stable the niche will be in the future, how "big" is the site already (room for improvement?), how many competitiors there are, how much traffic is the site getting (could ctr be improved) etc. Other factors like pagerank, SERPs, domain value, etc will all come in as well. It really depends on the site. It's hard to suggest a guideline without seeing the site first. It could be worth anywhere between 3 months worth of revenue and 2 years.