It isn't hard to fake this at all I am afraid. Spotting it will depend on how sophisticated the person doing it is.

My personal preference would be not to use analytics as the means of counting it. Doing that you are going to be slightly limited in the metrics you have available and will always be "correcting" data and looking for problems rather than measuring more correctly and having problems spotted.

I'd have a script on page that logs that checks for a referrer and it if matches the pattern for website B creates a log record instead.

You then have the ability to set your rules. For instance if you get 2 referrals from the same IP a second apart would you count them? What about 10 per hour 24 hours a day? You can also log the exact timestamp with whatever variables you want to collect, so each click from the referring site might be recorded as:

• Time stamp
• Exact referring URL
• User agent
• IP
• Last visit (based on cookie)
• Total visits (based on cookie)
• #pages viewed (updating cookie on subsequent page views )
• and so on

Analytics doesn't give you access to the data in quite the same way. I'd definitely want to be logging it myself if the money involved is reasonable.

Both are quite different, so it really depends on what you are after.  I'm actually a big fan of majestiseo (just to confuse things further).  OSE is good for understanding the big picture. However I find that its crawl isn't anywhere deep enough for the stuff I work on - particularly in terms of deep pages on large authority sites.  Example:  links from the bbc are almost the holy grail for some of the projects that I work on, but OSE often misses them.

Ahrefs is better, and majestic goes deeper still. The down-side of that is that you get a lot more low quality stuff to sort through.

In terms of majestic v ahrefs, ahrefs definitely wins in terms of interface / tools.  I'm an excel guy though, so it is all about the data for me - hence majestic being my "weapon of choice".