On Genea-Musings, I usually post a theme post in the morning, including:
1) Amanuensis Monday - this is usually a transcription of a document (deed, probate, military, naturalization, etc.). I post the image(s) of the document, craft a source citation and discuss it in the context of my ancestral families. 348 posts to date. I have a list by name at http://www.geneamusings.com/p/amanuensis-monday-posts.html.
2) Tombstone Tuesday - this is usually a photo of a gravestone I've taken of one of my ancestors (and sometimes not), or a Find A Grave memorial of one of my ancestors. 54 posts to date.
3) Tuesday's Tip - this is usually a search or research tip for readers to use, based on my experience and research. 174 posts to date.
4) Wordless Wednesday - this is a photograph, or a set of photographs, from my ancestral families or my genealogy experiences. 335 posts to date.
5) Treasure Chest Thursday - this is a document for one of my ancestors. I post the document image, transcribe or extract information from it, source it, and discuss it. 360 posts to date.
6) 52 Ancestors - this is a biography of one of my ancestors, based on my research, done in ahnentafel order starting with my great-grandparents. It has the link to me, the identity, individual events, shared events, notes and sources based on my research. 148 posts to date, with a list by ahnentafel number at http://www.geneamusings.com/p/ancestor-biographies.html.
7) Surname Saturday - this is a summary of one of the specific families in my ancestry. I am currently in the 8th great-grandmothers, having done all of the later generations! 367 posts to date.
8) Saturday Night Genealogy Fun - this is a theme for other geneabloggers to write on, and I offer my own thoughts. I've told a lot of family stories in this series. 393 posts to date.
9) Best of the Genea-Blogs - I want to give credit, and a link, to other geneabloggers who have written great blog posts each week. I also link to others who write Best Of posts during the week. 476 posts to date.
Astute readers know that I have been doing Treasure Chest Tuesday, rather than Tombstone Tuesday and Tuesday's Tip posts, on recent Tuesdays. I ran out of my own tombstone photographs, and I've run through many of the potential tips.
Each post label is on my right-hand column on Genea-Musings and you can click on them to see the full list of posts for that label.
Note that the Geneabloggers website has a longer list of daily themes that have been developed over the years - see http://www.geneabloggers.com/daily-blogging-prompts/ for the list.
So, to answer my reader's question: I do these theme posts for four reasons:
1) First, to "advance the genealogy ball." I gather information about my ancestral families and draw conclusions about relationships, names, dates and places based on the totality of evidence available at the time. Extracting and transcribing information in documents is one of the best ways to enable analysis of and support conclusions. Crafting a source citation is helpful to my research and may encourage others to follow my example. Creating a biography helps me review the information I have in a formal way, enables me to do more online research about the week's subject, and spurs me to find more resources for the week's subject.
2) Second, to support and encourage the geneablogger community. I provide a weekly theme for geneabloggers to write about. I provide a weekly list of blog posts that I liked that might help and inform readers.
3) It's Cousin Bait. Each blog post about an ancestor or ancestral family provides an opportunity for a cousin to find me - someone that shares my ancestry with the subject person or family. This provides an opportunity for collaboration.
4) It provides a significant volume of blog posts - typically about half of the 15 to 20 that I produce in a given week.