We have shut down the Import Keywords tool.
We added the Import Keywords functionality in late 2015 based on feedback from users who wanted to get volume data for keywords they had stored in a text or Excel file.
Initially we put a limit of 10,000 keywords that a user could enter into this tool at a single time. There was no limit on the number of times this tool could be used. So users now had the ability to get volume data for thousands of keywords everyday.
Sometime last year we noticed that the Import Keywords functionality was putting a lot of strain on the API, and brought our server down for a few hours. On further investigation, it was apparent that we had thousands of bots abusing this tool. We then tried our best to block these bots from using the tool, but we failed to do so as it is impossible to block bots from using a chrome extension resource. We spent months trying to find solutions, that would keep the bots at bay, but still let genuine users use the tool.
Unfortunately the bots won. Due to the constantly increasing load on our servers, we were left with no choice but to shut the Import Keywords tool down.
Customers of our paid keyword tool, Keyword Keg have not been affected, as Keyword Keg is a web based tool (not a chrome extension) and cannot be abused by bots. Keyword Keg will continue to let customers import files with upto 50,000 keywords per file, and this can be done as many times as permitted by their subscription plan.