If you do create Wikipedia entries be aware that there are rules about businesses on the platform.
A lot of PR agencies got publicly burned while trying to promote their clients there.
Which led to Wikipedia publishing this
And check out the PR institute rules in the UK
Basically, don’t expect this to be an amazing source of new business.
However, I have an other option to offer you which may work better.
Answering questions around your topic of expertise and interest and inspiration is definitely somewhere you can shine. It’s not open source, so nobody can edit your submissions and you can get upvoted and become and “expert” quite quickly.
The key is to start in an established niche where you are confident.
Here are some easy tips on writing replies with a marketing slant.
Using Wikipedia and Quora for Marketing