While checking the progress of this site on the SERPs, I noticed huge differences in positioning due to the frequency of some of the words. The site I used only checks the first ten pages of Google's SERPs so the really useful phrases that people are likely to search for aren't showing yet.
What I did to test the effect of word frequency was to add various user's names to the search because the more someone posts, the more their name appears on the site. These are some of the phases I found appeared on the first ten result pages with the position next to the name. Note that the phrases where I included the word "Lawrence" came higher than the same phrases using other user's names with less posts. I got this data from
http://www.rnk1.com/
eshop forums 1
eshop forum 5
ecommerce forum 409
ecommerce forums 99
zencart forum 395
madhatter 371
ecommerce lawrence 4
ecommerce blush 356
ecommerce kate 287
eshop lawrence 1
eshop blush 11
eshop blushfashions 1
eshop kate 10
eshop nick 7
eshop debs 3
edible graphics 205
blushfashions 500
We seem to be doing very well with "eshop", now all I need you to do is keep using the word "ecommerce" in your posts
When I get the chance I'll check these phrases again to see how they are progressing and hopefully add some more to the list that weren't listed on the first ten pages the first time I checked them.