I realized I take our guild's use of Roster a bit for granted. We have 219 out of 316 updating, about 70%. Apparently, this is fairly high.
I felt I should probably share some of the strategies we use to encourage our member base to get moving on this, maybe trigger some neat discussion on other ways we can get towards 100% or help other guilds climb up from the lower %'s.
First off, TOTAL BUY-IN from your top people. All the guild leaders and officers should upload their data into Roster at least once. We had a GL who wouldn't get on Roster and a few times we ran into members who figured that it wasn't 'necessary' if the guild leaders didn't do it. If you're just a lone officer in your guild who thinks 'it might be neat to run Roster', but no one else in the guild has yet to learn WHY it's cool, your success rate will be pretty low.
Second off, MAKE IT SIMPLE. Take the time to learn how to pre-configure an Installer of UniUploader so that your members have NOTHING to think about. Setup UniAdmin so you can easily push out the correct versions and right settings. Be prepared for people to 'not get it' and still goof it up in silly little ways that you'll have to help them with, even if they're super savvy.
Next, PUSH IT EVERYWHERE. Make sure you talk it up in guild chat all the time. Link it constantly in your forums. Have LOTS of places on your website that lead back to the UniUploader pre-configured downloader. Get tons of people using SigGen for their signatures so people say 'hey! I want one!'.
GIVE THEM A REASON! Sort out what addons and Roster functionality are useful to your guildmates and make sure 1) they're working and 2) the people who need it KNOW about it. Some fantastic 'lure' add-ons to Roster are the max.Resist (for the gear obsessive) and Missing Recipies (for the folks skilling up professions or recipe obsessed).
SPECIAL BENEFITS - we occasionally run events ONLY for people who are using Uni (or at least upload regularly) - and make sure to be vocal about it. One of our guild bank managers also regularly checks the Missing Recipies to see if anyone needs things just collecting dust and sends it to them.
Optionally, you can even have an 'Initiate' phase that you are required to Upload to Roster to qualify for Membership (along with any normal requirements). We don't do that with our guild, though we do require a forum signup. People still in initiate phase in our guild aren't allowed to request from guild bank, so people are pretty on the ball about meeting 'Initiate' requirements.
Chime in with some of your strategies to get people uploading!