2. The method of claim 1 , the method further comprising: selecting one of the plurality of organic search keywords based on the assist-to-last ratio; and generating the recommendation to prompt the content provider to accept or reject adding the selected organic search keyword to the content provider's paid keywords; and wherein selecting one of the plurality of organic search keywords comprises, for each of the plurality of organic search keywords: comparing the assist-to-last ratio for the organic search keyword to a particular threshold assist-to-last ratio; and determining whether to select the organic search keyword based on the comparison.
2. The method of claim 1 , the method further comprising: selecting one of the plurality of organic search keywords based on the assist-to-last ratio; and generating the recommendation to prompt the content provider to accept or reject adding the selected organic search keyword to the content provider's paid keywords; and wherein selecting one of the plurality of organic search keywords comprises, for each of the plurality of organic search keywords: comparing the assist-to-last ratio for the organic search keyword to a particular threshold assist-to-last ratio; and determining whether to select the organic search keyword based on the comparison. 3. The method of claim 2 , further comprising: determining reaction data based on whether the content provider accepts or rejects the one or more organic search keywords; and determining one or more subsequent recommendations based at least in part on the reaction data.