Say you write a blog hosted on Blogger and the following email arrives in your inbox - How would you respond ?
>>Nice blog. My friend reads your writing on a regular basis, and talks about it quite a bit. I just checked it out. Being a blog designer, I have to say the site looks great, but I noticed something I thought I should bring to your attention. You probably know this already, but you are doing your blog a great disservice by not having your own domain name.
I'm sure you get tons of links to your writing, but instead of those building up your domain and it's value, all those links are going to Google's blogspot domain. I know it's a hassle to move domain and save all your old posts, but I really think it's worth it for you.
Keep up the good work.
ps. If by chance you are considering transferring to your domain, I do have some skill in that area.
Ian [website address]
"Save Your Blog. Transfer to your own domain today!"
Spoiler: The email sender actually runs a web design company and that's just another marketing email but very smart - he understands the weak points of Blogger blogs and uses them to sell his service.
I would have probably confused this as some very "genuine advice" from a concerned blog reader had I not received three different emails with the same text. Related: Move from Blogger to WordPress.