This makes me pretty leary about trying any new services including Fiverr services. It is obvious Google HATES being manipulated and they have immense resources to battle this on an ongoing basis. You will always be able to 'game' the system and 'cut corners' by doing things artificially rather then letting the backlinks occur naturally. But it seems like maybe in the long run it may not be worth 'rolling the dice', at least on your most important site(s).
Has anyone heard any theories on what Google is doing differently? More importantly, are there any services our there anyone has used for some time for backlinking that didn't lose at least some SERPs from 3.3? On the keyword phrases we did backlinking on, we say on average about a 4 SERP drop (from top 4 to around 6-10) and these are on keywords that have ranked high for many months.