We've invested very heavily in building out a solid infrastructure for extracting data. We want to make sure that the product Just Works for our users, and that includes rotating IP addresses (you don't have to fiddle with your own, we have access to a pool of thousands).

Robots.txt is a tricky balancing act. It was first conceived in 1994, and was designed for crawlers that tried to suck up all the pages on the web. ParseHub, on the other hand, is very specifically targeted by a human. A human tells ParseHub exactly which pages and which pieces of data to extract. From that point of view, ParseHub is more like a "bulk web browser" than a robot.

Here are some examples that make this line blurry. If I tell ParseHub to log into a site, visit a single page, and extract one piece of information on it, does that violate robots.txt? If yes, then your browser has been violating robots.txt for years. The screenshots of your most visited websites are updated by periodically polling those sites (and ignoring robots.txt). My browser is currently showing a picture of my gmail inbox, which is blocked by robots.txt https://mail.google.com/robots.txt

More importantly, your computer and browser already do a lot of robot-like stuff to turn your mouse click into a request that's sent to the server. You don't have to write out the full request yourself. Is that then considered a robot? If not, then why is it considered a robot when ParseHub does the same (again, assuming a single request) thing?

Furthermore, some sites don't specify rate limits in robots.txt, but still actively block IP addresses when they cross some threshold.

It is far from a perfect standard, so it makes a lot of practical sense to have the ability to rotate IPs, even if it's not appropriate to use that ability all the time.

Our goal here is to be able to distinguish between the good type and bad type of scraping and give webmasters full transparency. Obviously this is a hard problem. If you have any feedback on any of this we'd love to hear it.

ps. we've tested our infrastructure on many Alexa top 100 sites and can say with moderate confidence that it will Just Work.

pps. if you're a webmaster, having ParseHub extract data from your site is probably far preferable to the alternative. People usually hack together their own scripts if their tools can't do the job. ParseHub does very aggressive caching of content and tries to figure out the traffic patterns of the host so that we can throttle based on the traffic the host is receiving. Hacked together scripts rarely go through the trouble of doing that.