I've noticed that the websites ranking above mine are constantly modifying their site. Everytime I refresh their page it shows it has been modified. Is this helping their ranking? If so, how are they doing this?

[SVinson]

Will this help my ranking?

[RichardTaylor]

Is the niche/industry based around time-sensitive stuff?

[SVinson]

No, nothing is time sensitive. Could it be updating "live" from a twitter feed?

[pqdbr]

Couldn't it be A/B/C testing of sorts ?

[EvolveCreative]

I'm not really sure if it will help your ranking, but I can tell you that I've experienced large spikes in traffic every time I change a theme on my Wordpress blog. As much as I hate to say it, Google loves the freshness.

[irvingw]

fresh content keeps the spiders coming around and keeps google happy so you should look to refresh content on your pages as much as possible

[SVinson]

I do keep fresh content on my webpage but this is like them having "live" content.