Taking a look on my logs and history files, I've found that whenever my site has improved its ranking, the search terms returned more results than previous check, and viceversa, when I go down, there are less results.
As an example:
Search for 'keyword' on day 20, I migth be #8 among 20000. Then I'd search again for the same keyword on day 23, and I'm #6 among 24000. And perhaps, if the next time I check there are 18000 results, then I'll be #11 or so. This numbers are not real, only ilustrative.
I've seen it happens almost always (let us say, about 90% the checks I've made in 18 months) with three diferent sites. Until I noticed this, I was completely convinced that the less competitors, the best... but I migth have been mistaken.
I've posted it more as a curiosity than as a problem, but I'd like to know if this happens only to me or somebody here has noticed.
Greetings,
Herenvardö
