@Bill Kirkley, well, there is one BIG, practical reason to do things this way and that reason is called bots. There are web crawler bots that access your site ALL the time as a guest and they are essentially indexing all content on the website. By excluding "guests" it dramatically reduces the load on the servers by way of keeping bots out of the images - or at least that is my understanding.
A technique to reduce web crawling bots is to exclude indexing in the server configuration files. The drawback to that is that if sites do not index your site and then a person's Google search may exclude content here at H-M when searching for help on a machining topic. Since people aren't usually doing photo searches but rather, topical text based searches - excluding bots from indexing images is a smart thing to do - but it requires real people to register.
One of the recent problems that compounded this is that our members love photos! The bigger the better! And MORE is not enough! We have tried to find the right combination of image optimizers, photo resizers, etc. so as to allow for the most high quality photos at the highest quantity possible because that is what our membership likes in the original content found here. So, allowing guests to view those presents problems when viewed from a web indexing perspective. We continue to adjust these settings to try and make everyone happy.
@Ulma Doctor, certainly there are different perspectives to take on this topic. And it is very easy to get cynical over ad displays - sometimes I will just close a site that is laden with popups etc. I don't think popups are on H-M are they? If they are I would like to know.
Becoming a donating member actually reduces the number of ads that a user sees. Non-donating members will see ads and those ads are driven by Google's engine which really has nothing to do with H-M doing any direct marketing - ALL Google Adsense content is generated by your search criteria and internet habits. Google Ad revenue is used to support the site expenses but there is no direct marketing ad campaign happening on the site outside of our Site Sponsors. Google Adsense revenue is useful because not all members are able to donate at the $10, $25 or $50 annual donation levels.
Another positive reason to exclude guests is that they can be sources of spam. Getting a person to register keeps spam out and people who do not share our interests out. People who register and cause spammy problems for our members are promptly removed. Registration is a very good gate keeper for this reason.
Another positive way to look at the registration requirement is that getting a person to register does make it much easier to directly communicate with regular visitors of the site. This comes in handy when somebody has technical problems and requires support or a mass communication is necessary for the broad membership. MOST importantly becoming a registered member opens up all possibilities for learning and sharing on the site.
Ads can be problematic, but we think we have struck a good balance between what some other sites do and that is inundate you with popups and spam like content. We really try not to do that so we can stay focused on making chips. If there are any problems that people would like to make aware to me, please PM me directly
@vtcnc - I don't get paid for this and am a donating member - so outside of my day job and family time I will take a look at your suggestions or problems and try to help. We have an excellent staff of moderators and admins that work behind the scenes and will try to make positive changes where it makes sense.
Bryan