This is NOT black-hat SEO. You may see some results, but your SEO company may not be doing you any favors. Some SEO practices are designed to keep you on-the-hook. When you stop using their services, your results go right out the window! What?
SEO should be a long-term sustainable result that enhances your brand. Look for these clues to determine is your SEO company is more interested in their pocketbook than in yours.
1. Using a forwarding phone number that YOU DON'T OWN.
About the only place you should consider doing this is MAYBE a Pay-Per-Click scenario where you are trying to evaluate your call quality or count leads generated from the advertising effort. The sales pitch for using a forwarding number is the ability to track the calls generated. What we are seeing however is the forwarding number is placed on Google MAPS, all submitted directories and landing pages. If the website owner, for whatever reason, decides to stop using the SEO company using this practice the response from the SEO company is to pull a report showing all the calls he's getting. When the SEO services are cancelled, so is the forwarding number!
2. Claiming a Google Business Page on behalf of the client and NOT transferring ownership to the client.
Trying to wrest control of a Google Business page you didn't create and for which you don't have login access is like trying to get into someone else's safety deposit box. It is very difficult to convince Google that you are the business owner and should be in control of your own Google Business page if you didn't create it. If your SEO company did not give you access to your own Google Business page, you need to ask why and demand that you have ownership access to that account.
Your Google Business page is how you control the information in the Google MAPS listings. In the worst practices scenario, this page will list the SEO company's 2nd website representing your business AND the forwarding phone number they are using for you. All of the directories and citations used to promote your Google MAPS page (this can be literally 100's of citations and directories) all point to the SEO company owned website and forwarding number as well.
3. Creating a second website for your business
Similar to using a forwarding phone number is the practice of creating a separate website for your business or independent landing pages. The first thing wrong with doing this is it dilutes your brand. Very often the site is very bad quality, attracts only a few keyword searches and rarely gets updated. It also uses the forwarding number, not your actual business line. Typically the business owner has no control over this website.
4. Posting reviews on review boards that are not polled by the search engines
Google pulls reviews from a few credible sites and usually not a site unique to an SEO company. That's not to say those reviews aren't useful but again, what happens to all those reviews if you decide to part ways with the SEO company you're working with.
5. Publishing a link to their business from your home page.
This isn't usually done by an SEO company but you see it a lot. The web designer in this case will advertise his own site at the bottom of your site. This is great for self promotion of the SEO company and typically bad news for the website owner. If you want to give your web designer kudos, do so on review sites and other appropriate venues on the web. Linking to anything but internal pages on your home page will cause your site to lose SEO value and traction.
THE BOTTOM LINE
The bottom line is this. If an SEO company has your best interest at heart, it would spend all the time and effort promoting YOUR website and phone number - not something that will disappear when the SEO company leaves your service.