What do you like best?
I love SpyFU, I'm able to compare keywords that my company ranks for - and continuously compare to our top competitors. I like that it shows us automatically competitors that we may not know were competitors. It even breaks it down to what keywords you're both overlapping, and which keywords are unique to each site. I can see the monetary value and the amount of traffic that is generated for those specific keywords, so I know whether they are worth going after or not.
What do you dislike?
The exporting feature could definitely be improved. I can't export any of the graphs, just the data. The comparison tool also only shows a few competitors in the graph at once, I wish that I could make the viewing window larger. I also wish it explained more what some terms meant, like "ranking difficulty" - I don't know what the scale is, so I can't really evaluate the number they provide.
Recommendations to others considering the product
It's a pretty good price compared to other software. There's a little bit of a learning curve, but that's how it is with any software using large amounts of data.
What business problems are you solving with the product? What benefits have you realized?
I'm able to see what keywords we are not ranking for, and the traffic that we are losing as a result, so thus I can focus our SEO strategy for those specific keywords. We also can see when we drop off the first page for a particular keyword, so that's helpful.