We've been able to get a slight increase in traffic since MayDay. It was done through lots of hard work [to get to] pretty much normal in terms of traffic
Ok, so you have nailed down the precise nature of the Mayday update, analysed the effects on your site, identified an escape vector and followed it dilligently, always increasing your traffic along the parameters you initially projected?
Then an equally plausible statement is
"We got hurt initially before traffic slowly returned to normal as per many updates. In the meantime we did some frantic fiddling which may or may not have had an impact, whether positive or negative"
I'm not trying criticise you directly, but this thread has been sadly lacking in critical analysis for some time. Too much of it is anecdotal, or just simply an opportunity to moan.
FWIW, I see a BIG uplift in traffic since 1st SEPT (20% above trend) with a corresponding drop in conversion rate, so sales are broadly static (on trend). Referrals shifted at precisely the same time. No visable change in ranking.
A referral shift on 16th Sept, another 6th October- both traffic and conversion neutral (relative to the 1st Sept).
Then the biggy. 12th October, huge referral shift. Traffic-neutral, but conversions back at pre-Sept level. In other words, we are now 20% up on sales. The referrals are NOT the same (even particularly similar) to the the pre-Sept level. It looks alot like a 6-week algorithmic test-program for our site, and we passed.
By the way, we did NOTHING fundamental, just added new pages at the normal rate- although we did get a nice link boost being first-to-market with a number of product releases.