If you receive free products for review, you're going to want to read this and make sure your links to products you review are set as "no follow".
What are "no follow" links?
This tells Google (and other search engines) not to pass on "link juice" (which is like reputation, energy, and recommendation all rolled into one) from your website to the website you are linking to.
Why does it matter?
Google's ultimate goal is to give users the best experience possible (which makes them valuable and useful and makes them lots of money). Which means - if someone is giving you a product with the hope that you'll give a link to their site...this stops that. This has been an unofficial "best practice" for awhile.
Why do links matter?
Google used to rely heavily on words (and we've all read terrible blog posts that stuff a phase into sentences over and over!). Now they rely on lots of things including: words, phrases, other on-site things, and off-site things (like links back to your site).
It used to be that lots & lots & lots of links to your site meant that your site probably had good information and was something users would want to see.
But...when everyone catches on to that....it gets exploited and and link farms (pay us $50/month and we'll give you 300 links to your site) and crappy, random guest blogging happens.
How did it work?
Product A sends samples to 500 bloggers to review their product.
The bloggers do their thing and dutifully link back to Product A's website.
This makes it look as if Product A is suddenly much more useful and valuable than maybe it actually was.
In addition to that, let's say 85% of those 500 bloggers are just in it for free stuff, so their review isn't great, their copy isn't helpful, and overall it drags down the usefulness of Google search (because the algorithm is being misled by all of those links).
So this is Google's official "don't do that" warning.
Musings about marketing, social media, and small business.