tc_optimise is an implementation of software by touchclarity. It is used for targeting promotional campaigns.
From the first visit, Touch Clarity Targeting (TCT) starts building a profile of each visitor, and recognizes them using an anonymous first party cookie. Fully automated, the software learns in real-time which content will best achieve a given goal for each visitor and triggers the serving of that content.
source - from their website.
Sounds like it swaps out content to show promotional campaigns based on user profiling.
My gut feeling? probably harmless, since they have content stuffed into <noscript> tags, but all this certainly doesn't *help* SEO.
For a glimpse of what it will do to the engines, find a site using TCT (it's easy - Google "tc_optimise"), and look at it with a LYNX browser.