I have seen that with the various backlink checking web sites, that it is clearly visible when someone buys 25, or 1000, backlinks. It doesn't make sense. They have maybe one backlinks being added a week, then one day with exactly 25 or precisely 500. Very odd. This MUST be 'black hat' backlinking. How does the big 'G' view this in terms of banishment, etc.? Would that alone flag an alarm with consequent negative reaction toward a web site? Or is it OK? I have seen major web sites that seem to have done this. No penalty, apparently. And it was loads of backlinks, sometimed as many as 10,000 or 15,000 at a time. It looked more like a chart depicting sales of equities. There go 15,000 shares....now another whopping 1000,000....wow!!! So do these CLEARLY statistically-improbable spikes to discrete base-ten values imply fraud?? Looking by eye, it does to me! So the question is: Are backlinks, even cheap no-follows or social, blog comments, etc., dangerous to add all at once, on one day? Or does this look to G like something interesting happened, a new article published maybe, something that made people interested that day? Or is it not that dumb. To me, it looks unnatural. I can't imagine machines would not be able to find far more subtle irregularities, let alone something like this. So the Q is: Are any/all backlinking services where one receives more than one link, bad if not done (drip-fed is the term I've seen people use) over time????