Good question!

Domain expertise leads to better visibility:

• list of top 5 experts for a hashtag are always visible in the right column;
• results in the predictive search are also sorted by expertise (both hashtags and users);
• priority in the news feed (for example, if user follows a hashtag and there are too many posts, priority is given to authors with higher expertise in that specific hashtag).

But expertise can be also useful in other ways:
When objects are being edited (for example, multiple icons are proposed for the same hashtags) the value of your vote on updates (accept/reject) is based on your expertise in that specific object.

For example, you have a lot of expertise in #beersaturday and as the result you can select the icon for that hashtag.

It is not enough to have a lot of VP, but user has to have a lot of expertise in that specific object to make edits.